What you're thinking about doing sounds exactly like us a few years ago. Like you we were CA residents. We moved to an apt in TX, then put our house in CA on the market and then we both retired. I was uneasy about moving directly to Livingston (domicile). I didn't want CA questioning us on residency status, like some states are now currently doing, so we decided living in an apt was fine and it gave us time to customize our coach to fit our lifestyle. When our coach was ready, we headed to IN to pick up our new home. Our King Aire is our first RV. Do we plan to do this forever? No, but for now, it's great to be able to 'live' all over the US and it certainly beats the high cost of living in CA and especially Silicon Valley.
We like lots of amenities and we carry a lot of stuff, so a 45' coach was a must for us. One of my earlier threads on the Newmar forum was on amenities and carrying stuff. Actually a few more feet would be nice, but....

Since we're too big to stay in national parks, we just stay nearby, usually in a RV park with 50 amp service. With two satellite dishes on the roof, one for HDTV and one for internet, most national parks have too many trees for us to get a clear signal, so even if we were smaller, we probably wouldn't stay in them. I don't think we've missed too much by staying nearby, instead of in the parks. We actually do fit is some state parks and USACE parks. We even took our King Aire to Alaska in 2010 and hope to do so again in a few years.
I know it's hard to say when is the right time to make such a drastic lifestyle change like you're considering. For us, life threw us a curve ball medically speaking, so we knew it was time to retire and once we retired, we no longer needed to be in CA. Others on this forums had different reasons. For many, being a full-timer is cheaper, but if you're buying a King Aire, it might not be, but it's better than giving a large chunk of it to CA.
Good luck with your decision,
Sue