As you don't have kids at this point, your options for places in Sacramento to buy a home are wide open. There are a lot of older smaller homes out there with small price tags. And even if the market goes down, they are unlikely to put you under. The areas where these homes are located are not any worse than where the rv parks are located.
If you total the payments for the truck and trailer and the cost for the park, you could get a small home for around the same.
Sacramento gets very hot in the summer so that AC will run almost constantly in an RV.