This is, of course, unknowable.
That being said, if somehow tomorrow all the Mormons woke up as plausible non-Mormon equivalents, I suspect that Utah would be a fairly Democratic state, with Salt Lake City as a Denver-esque city with a lot of White liberals and Provo as a Boulder-style college town. St. George would probably vote like Bend. Northern Utah and rural Utah would probably remain Republican but I think on balance Utah would be a Dem state since so much of the pop. is in the Wasatch front.
Idaho on the other hand would only probably vote slightly more leftily. Democrats would probably win Pocatello and Rexburg but it would remain a R state.
Nah. The plausible non-Mormon equivalent of BYU would be an evangelical Baptist university, not University of Colorado, in my opinion.
I would add that Salt Lake City is already full of White liberals, the city is 66% non-Hispanic White and gave 66% of the vote to Hillary Clinton in 2016.
BYU is a fairly prestigious and competitive institution, unlike most hardcore Evangelical Baptist Universities. Moreover, Provo is very much a college town. I suspect BYU in this parallel universe more closely parallels the many universities which have some religious affiliation but are nevertheless home to pretty liberal student bodies, like Duke or Georgetown.
SLC has a lot of White liberals but the metro area has a lot of Republican suburbs, significantly more than Denver, or really any other interior West city other than Boise.
