There are a lot of posts in here under Oregon that offer mucho advice.

Your question is fairly wide open - so perhaps one could ask: Are you at all intrested in exploring some of the Coast, where there are some hiking spots and smaller towns - or perhaps trapsing around some scenic lakes, or getting more up into the mountains, etc.

We love Mt. Hood and Timberline Lodge - but there will be snow there in Dec. You could continue on down to say Bend/Central Oregon - and maybe further down to around Ashland - a cute college town in Southern Oregon - where there is also a lot to do.

Oregon is beautiful, and the fact that there aren't any sales taxes makes it even better. I suggest:
Crater Lake National Park
Might be too cold, but whale watching is always fun
Pilot Butte
Lava River Cave

This website should be very helpful. http://www.guidetooregon.com/regions/index.html
Which 2 or 3 regions of the 7 do you want to visit?
Pilot Butte in Bend is worth about 20 minutes but you will have to hike up since the gate is closed until Spring.
If you don't like skiing, learn to snowshoe.
You can rent snowshoes at the "Powder House" which is on your way to Mt. Bachelor.

Bend would fit your requirements. I went over NY last year and loved it. Enjoyed snow shoeing, snowboarding, and checking out some really fabulous microbreweries in the area. Good caving near Bend if you're interested in that as well.

The information you need about caving in Central Oregon. http://ohdgrotto.caves.org/caves.html
Many of the caves closed on November 1 due to resident bat populations.
If you do come to Bend over Christmas, you will really want to come back sometime in the Summer.

Most of the small towns on the Oregon fall into the "quaint" category (e.g. Cannon Beach and Yachats but not Coos Bay and Florence) and, in the Columbia River Gorge, Hood River fills the bill.

The Columbia River Gorge offers many hiking opportunities: http://www.portlandhikersfieldguide.org/wiki/Columbia_River_Gorge_Hikes

HTtY

Oregon in December will be very wet and cold and probably windy on the coast, wet and grey in the Willamette Valley, and cold and snowy in the Cascades and Central Oregon. However, it's likely to be sunny in Central Oregon more days than not.

You don't mention where you're travelling from but if you are planning to rent a car be sure to get a snow-worthy car for crossing any mountain passes that time of year. Bend is a great location for all kinds of outdoor winter activities including skiing if you choose. A very nice loop would include a trip through some of the small towns in the Willamette Valley, up the Columbia Gorge with a stop at Hood River, up to Timberline Lodge, then to Bend. That might be alot of travel for 8 days depending on how much time you want to spend in each place. Or you could reverse the loop.

I've lived in Oregon all my life and I find some of the small Oregon Coast towns to be a bit dreary, rather than quaint, in the middle of winter, but that's me. Also, I don't know if you've been to Portland, but it's a great city with excellent nearby hiking, fabulous healthy food, and lots of interesting indoor things to do like art museums, music venues, etc.

The town near Bend that fits my definition of quaint is Sisters.
The trip over 22 and US 20 over the Santiam Pass should show you enough snow on the way to Sisters and Bend. You might want to visit the Tower Theater in Bend for a great show. http://www.towertheatre.org/
If you want to avoid snow, head for the coast and go south on US 101.