Hi Marcia, I'm going to move this over to Sleeping for Toddlers as your LO is over 1yr.
We've done a trip from ND to CA for the past 4yrs in the spring... ours is a 2hr time difference. I always think it's worth it, but that's partly due to the fact that winter is so long for us and I'm definitely ready for a break. We also go with my parents, so have plenty of help!
As far as flight times, I think morning/mid-morning works best, depending on how early you have to be at the airport. This way, you make it to CA by lunchtime/early afternoon and can get a nap in (maybe in the car) and have time to settle in before BT. Early afternoon works pretty good as well, esp if you think there's a chance he may sleep on the plane.
In terms of once you get there, it kind of depends on how flexible he is. You mention that you often cap his nap. I think that'll work to your advantage in that hopefully the first day or two he'll be able to take a nice, long nap so you can push BT a bit. My DD was not a very flexible toddler, so we never expected her to move her routine much more than an hr... her normal wake-up at home was 6:30, so we were often up at 5:30 in CA (but that's 7:30 ND time, so really pretty good for her). My DS1 is very flexible, so he would nap long and we would push BT and he could probably make it back to close to his normal wake-up (which means almost 2hr change) within a couple days. As they've gotten older, it has become much easier.
So, I guess I would try to set your expectations not too high. Know that there will be some OT and it might not be the most restful of vacations. But, IMO it's totally worth it to get away, enjoy some family time, and hopefully lots of sun!