I am planning a 14 day trip from Portland Oregon to San Francisco area. Planned dates are September 16th - 30th. We are a senior couple. We will be picking up a rental SUV at Portland Airport for the trip. We will not drop the car in San Francisco. We are meeting up with family and heading on for a family wedding and will spend a couple of weeks in San Diego.

Interests are good scenery, local culture, short accessible hikes, art and other museums, food. My wish list includes the Cascade Lakes Scenic Byway and Pulina Lake near Bend, a bit of the Oregon coast, some coastal redwoods, Coastal Botanical Gardens near Mendocino, Ft Ross Historic park, Pt Reyes National Seashore, and the Sonoma State Historic Park. We enjoy short accessible hikes. One person uses a walker. His stamina is ok, but he needs the walker for balance. Walks that are baby stroller accessible work. Curbs and a few steps with a hand rail are fine. Lots of stairs or rocky paths are not ok. Maximum length for a walk is 1-2 miles.

My first swipe at a 2 week itinerary. Please make suggestions!
Day 1 Fly East Coast - Portland. Arrive PDX evening. 2 nights in PDX area hotel.
Day 2 Costco run, pick up some groceries or whatever, and do something fun in Portland. We're seniors. The first day after a cross country flight is a recovery day. (This is also a slack day that can be used if we need to add a day somewhere later in the trip).
Day 3 Drive Historic Columbia River Highway to Hood River. Alternative - drive Mount Hood Scenic Byway to Hood River. Overnight Hood River. We drove the Columbia River Highway in spring a couple of years ago. I assume less water in waterfalls in September. Would the Mount Hood scenic byway be a good alternative?
Day 4 Drive Hood River to Bend. Maybe a couple of stops in the Hood River Fruit Loop if we have not done that on day 3. We visited Timberline Lodge on Mt Hood and Smith Rock State Park last trip and enjoyed both. That was during the spring. Would a revisit to either in the fall make sense? Overnight Bend 3 nights.
Days 5 & 6 Bend area. We visited Lava Lands and Lava Butte last trip. Paulina Lake and the Cascade Lake roads were still closed. We are looking forward to exploring both this trip.
(Alternative for the above is a few days in Portland? Backup plan if wild fires become a problem).
Day 7 Drive to the Oregon Coast. Do we aim for Reedsport to go through the nice canyon area on the way to the coast? Drive down the coast to Bandon. Overnight Bandon.
Day 8 Drive down the coast to Trinidad or Arcata. Looks like we should see good ocean scenery and redwoods.
Day 9 Drive to Mendocino. Include the Avenue of Giants. Mendocino 3 nights.
Days 10 & 11. Mendocino Coast botanical garden one day. The other day Van Damme State Park - the pygmy forest and pugmy forest trail. Explore Mendocino. The coastal walk in Mendocino. Maybe the redwoods at state park north of Mendocino.
Day 12 Drive south to Pt Reyes. Visit Fort Ross State Historical Park on the way. Overnight near Pt Reyes National Seashore.
Day 13 Pt Reyes National Seashore. Overnight Petaluma or Sonoma 2 nights
Day 14 Sonoma Historical Park
Day 15 drive to Walnut Creek area (meet up with family).

Suggestions please! What works? What doesn't? Good alternatives?

Thanks!

Question - would it make sense to take the West Cascades Scenic Byway between Portland and Koosah Falls the take the road through Sisters to Bend? It looks like this would be one day. New territory for us. And it frees up an extra day to explore Portland. That would be a plus.

Does this make sense?

To save a day (maybe 2) on your vehicle rental, take the red line light rail from PDX into downtown Portland. The end of the line is right outside baggage claim at PDX. If either of the days in Portland is rainy, go visit Powell's World of Books (full city block 3 floors). The TriMet system is great for getting around the city without having to scrounge for parking. Pick up the SUV When you are headed east to Hood River. Enjoy watching the kite surfers on the Columbia River. On the way to Hood River on I-84, there is a parking area in the median (left exit) to see Multnomah Falls. There is a tunnel under the eastbound lanes to get down to the base of the falls.
Leaving Hood River headed for Bend, just head south on OR 35 on the east side of Mt Hood to get to US 26. In Warm Springs, you will pass the Indian Head casino if you want to try your luck. Sometimes they have great acts so you might want to see who is playing on the day you go through.
Fill the gas tank at the big station above Madras (Indian run).
In Bend, be sure to visit the High Desert Museum. Since you have already seen the view from Lava Butte and visited the Lava lands Visitor Center, I suggest you not visit again. Last year someone drove up and over the sign next to US 97. It was sitting there smashed for months. A friend who will remain nameless put up a routed sign that says "Lava Lands" one night. He got in a little bit of trouble but is still employed by the USFS.
The trip out into the Newberry Caldera could be the highlight of the Bend area. If the road to the top of Paulina Peak is open, be sure to get to the top (almost 8K elevation. It has a great view of the whole caldera including Paulina and East Lakes.
I'll be back with the rest of the trip from Bend to the coast later. Post any questions you may have.

To save a day (maybe 2) on your vehicle rental, take the red line light rail from PDX into downtown Portland. The end of the line is right outside baggage claim at PDX. If either of the days in Portland is rainy, go visit Powell's World of Books (full city block 3 floors). The TriMet system is great for getting around the city without having to scrounge for parking. Pick up the SUV When you are headed east to Hood River. Enjoy watching the kite surfers on the Columbia River. On the way to Hood River on I-84, there is a parking area in the median (left exit) to see Multnomah Falls. There is a tunnel under the eastbound lanes to get down to the base of the falls.
Leaving Hood River headed for Bend, just head south on OR 35 on the east side of Mt Hood to get to US 26. In Warm Springs, you will pass the Indian Head casino if you want to try your luck. Sometimes they have great acts so you might want to see who is playing on the day you go through.
Fill the gas tank at the big station above Madras (Indian run).
In Bend, be sure to visit the High Desert Museum. Since you have already seen the view from Lava Butte and visited the Lava lands Visitor Center, I suggest you not visit again. Last year someone drove up and over the sign next to US 97. It was sitting there smashed for months. A friend who will remain nameless put up a routed sign that says "Lava Lands" one night. He got in a little bit of trouble but is still employed by the USFS.
The trip out into the Newberry Caldera could be the highlight of the Bend area. If the road to the top of Paulina Peak is open, be sure to get to the top (almost 8K elevation. It has a great view of the whole caldera including Paulina and East Lakes.
I'll be back with the rest of the trip from Bend to the coast later. Post any questions you may have.

Tom, Thanks for your suggestions! I will look at using public transit while we are in Portland.
Question. Would driving the West Cascades Scenic Byway from Portland to Bend make sense? It looks like it would be a one day drive. I'm assuming we would take the scenic highway as far as Koosah Falls, them take the road through Sisters to Bend. That would free up an extra day for Portland.

It works if you are going from Portland directly to Bend. I thought you wanted to visit Hood River after visiting Portland. Either way is less than 6 hours drive time from Portland to Bend. Several years ago there were large forest fires along OR 22 up to where it joins US 20 at Santiam Junction. Sisters is a pretty little town and it has the first gas station you will see after you leave I-5 on OR 22. With all the dead trees, it is not as pretty as it once was.
Te best of Oregon's waterfalls are along the old US 30 west of Hood River. The next best are off OR 138 west of Diamond Lake on the North Umpqua River. The best singular waterfall with a paved walkway to the top of it is Salt Creek Falls off OR 58 west of the Willamette Pass ski area.