Normally would say it depends of your priorities. Mazda’s in general are better quality vehicles overall than Subaru. I always found myself that subaru feel slapped together from a bunch of different part bins. They do have their cult following for some reason however, and they have a good all wheel drive system (note i said good, not necessarily superior).
If we where comparing a forester to a CX-5, then i would say go with your personal preferences and need of comfort, interior space, etc. The mazda have better handling and stiffer suspension set-up, better interior material and quality. The forester has bigger interior dimensions, visibility and a softer ride.
But since you are comparing the crosstrek to a cx-5, they are class and world apart. I say go for the CX-5. This is due to the fact that a crosstrek is a lifted impreza, which is subaru’s lowest cost offering. So at it’s core, it is an economy box, where as a compact crossover is a class above. For example, if you had the choice of a fully loaded crosstrek for the same price as a less equipped forester, the forester would still be a better quality vehicle. (Or same thing when comparing a Honda HR-V to a CR-V, the HR-V quality is significantly lower than the CR-V.)
I am in Canada and always put snow tires on my cars. No matter how good your AWD is, it won’t help you brake, so winter tire it is for me. In fact, i find AWD to be even more dangerous without winter tires, because you don’t really notice how slippery it is until you brake. Without AWD you are more aware of the road conditions (but accelerating a lot slower from a stop, lol). I know some people are using all weather tire as well. Put the tire you are used to, but i don’t recommend using AWD as a reason not to install winter tires if you normally would put them on.