Hi, I'm the owner of a Marquis SA Reward and I live in MN. I can tell you that I really love my tub. The Marquis has the Spa frog that helps with ease of mtce. I very rarely have problems with the water and when I do have slightly cloudy water, I know it's time to put in a new bromine cartridge. I still do my regular PH & Alk testing and I add a little sanitizer each time we use the tub (add after use). Weekly mtce includes shock and stain & scale. I clean my filters monthly, I have two sets that I rotate. I think between the frog system and the ozinator, things are kept simple.
From what I've read here, I think any major brand will be good against cold and snow.
Marquis has an excellent warrenty and I think it's one of the few that has a transferable warrenty.
Normally you would think "why would i want it transferrable" but since I bought my tub a year ago, Marquis has come out with the "Epic". I really want that tub! If I decide to sell my tub, I think a selling point would be that it still has all but 1 year left on it.
Definately take the time to wet test. Not only can you feel what each tub does, but it also gives you time to interact with the dealer to see if you are comfortable with doing business with them.
Good Luck