Just throwing out some possibilities:
U. of Utah - WUE rates, easy to be classified as in-state after the first year, well-reputed honors program (which should then provide smaller classes), lots of sun, and great opportunities for outdoors exploration.
UT - Dallas: Should get good merit aid and have been hearing great things about the CS program and they’ve been getting a lot more National Merit Finalists with their great scholarship offers. Should qualify for the honors program (and then smaller classes), and this gets lots of sun.
U. of Central Florida: Lots of sun, good CS, and should get good merit aid. The honors program should also help to shrink class sizes.
Cal Tech & Harvey Mudd would both be reaches, but they’re top-notch programs with small classes and lots of sun. Pomona, part of the Claremont Consortium with Harvey Mudd, also is well-reputed for CS, but has a bit more of a balanced student body than Harvey Mudd, and classes could be taken at HM.
While we’re talking reaches, I’m going to throw out Middlebury and Williams as possibilities. They’re not as sunny as the average American location, but they get about 6-8 weeks more sun a year than Seattle, so that might impact things. You’ll get the small class sizes, lots of outdoor opportunities, and they have good reputations for CS among liberal arts colleges. And a 15% admit rate (like Middlebury’s) is not great, but it’s three times better than some of the CS admit rates at schools that are overall less selective.
All of the reach schools meet full need (as they calculate it) if that’s important for your family.
Rose-Hulman in IN is going to give lots of small classes and has CS students placing well, but it’s a similar amount of sun as Middlebury and there should be good merit aid to boot.
I’d also check out Florida Institute of Technology. It’s closer in size to the ones on your original list, you’ve got tons of sunshine, and there are some interesting CS opportunities along the space coast. Would also expect some nice merit aid.