My fiancé and I have been planning a trip to Europe for our honeymoon for this August.

We we have a total of 10 days available including travel. We could always add a day or two if needed.

We want to fly to Rome and stay for 5 nights and do sightseeing. And then fly to Santorini for another 5 nights to relax and explore.

We live in California and have never left the country and don’t know if or when we will get another opportunity.

My question is if this is doable and would be an enjoyable trip? Or would it be overwhelming in the sense of so much traveling place to place?

Which airport in California? LAX or SFO? How far do you live from the airport?

The only travel issue I see is the number of flights in 10-12 days. Perhaps two to reach Rome, one to reach Santorini and how many to get home? You might have to fly to another city like Athens or back to Rome the day before your trans-Atlantic flight.

I live near LAX and have to accept that many European destinations involve connecting flights, but I also know that every connection presents an opportunity for delay, a missed flight and/or rerouting. And however you book it, the first and last travel days are long.

I'd stay in Italy. I wouldn't go in August, but perhaps you have no choice in timing.

If you can add 2 more days, fly into Rome and back home out of Athens it's theoretically doable as long as you aren't planning to spend any time exploring Athens (other than returning to Athens the day before you go home). Otherwise it's not enough time to enjoy, explore and relax in 2 countries. Personally, I'd stick with one country. Greece.

I live near SFO. We are open to picking one country but ideally wanted to do both. Our travel agent recommended it but I was worried we would get burnt out with all the traveling. Good tips on cancelations because I honestly didn’t even think of that.

August is the month we are going, and we chose 10 days for our honeymoon so we could have some days after to settle before returning to work.

Since we never have left the country we wanted to go big but we want to be realistic too. I know both Greece and Italy have so much to offer.

You have much control in making a trip to be less overwhelming. It appears you are assuming the number of places visited totally controls your destiny.
Rather than working in abstract, plug in ACTUAL trip details then decide if that is overwhelming.
I never fly directly back home from any Greek island in one day. To where I live, it takes insanely many hours to fly home starting at an insanely early hour in the morning in Greece. It is much much much easier to first fly to Rome, spend a few days, and then fly back home from Rome in my case.

Just remember it will be hellishly HOT in Rome in August ... up to 100°F you won't be happy standing in line under the hot sun, and won't feel much like sightseeing in a big city, in the circumstances. What are you expecting from this holiday .... think about it seriously. If you are thinking about some time on a beach, then Santorini will surprise & disappoint y ou. The West Side, on the Clifflike Caldera, is the famous VIEW -- but it you want to cool off, its beaches, on the other side of the island, are black volcanic GRIT, and walking on that is like walking on a diner griddle! Believe me. For that reason, many visitors pay $$$ for hotels on the rim of the View which have Pools. Really a budget-buster. If you fly to Santorini, I suggest you do 48 hours, just for the view, and then quickly take a ferry to a nearby island that has sandy beaches .... you have several choices ... Amorgos (Aegali area), Naxos, Antiparos, Sifnos.

Another option would be to fly in to ROME and go to an island like Malta for relaxing. In August, the sea breezes will help the heat. Since Italy has far fewer beaches than GReece with its many island, Italin beaches will be jammed.