All of these are relatively isolated NESCAC liberal arts colleges. You also indicated that you “really liked” Union – which is a former NESCAC.
If these schools appeal to you, then the obvious additions would be the other two isolated NESCACs: Middlebury and Williams. People who apply to your “favorites” routinely apply to Midd and Williams as well.
Both of these schools seem like they could be fits for you: (1) they are unusually wealthy and offer good financial aid; (2) they are strong in STEM, with good-sized computer science programs by LAC standards; (3) they are top schools for Division III athletics, and (4) they are conspicuously rural. Williams a bit more so than Midd in all of these respects.