I moved to UW Seattle for college from California. I also considered other places close to skiing (Portland, Boulder, Davis).
When I first arrived I was pretty down by the weather, coming from sunny Ca. I'm not sure where you're coming from, but it will definitely take some getting used to no matter what. On the other hand though, the PNW will grow on you pretty quickly. It sucks because when you move there for college, it's fall, which is basically the shittiest time of year in Seattle. Every day is darker and colder than the last, and there's no skiing yet. When the snow does come though, it's pretty awesome. I rode 50+ days a year while enrolled full time at uw. Unlike Tahoe or other places that tend to get a big dump once every few weeks, Washington is constantly getting snowed on. It's pretty common to have a few 6-10 inch days in a row, which I think is better than getting one 3 foot day every few weeks. Then summer rolls around, and it's awesome. You have the cascades and the olympics, which are pretty unreal.
At the same time, UW is a way better school than U-U, especially if you're considering science, engineering, or anything with research really. Plus theres Google, Microsoft, Boeing, Amazon, ect. Lots of huge companies, so a really strong economy, making it easy to find a job as well assuming you have a good resume.
SLC has some perks, but I honestly think if you chose it, it would be sort of "taking the easy way out". It's less of a risk, but also less opportunity than Seattle has to offer. Do it, and don't look back.