Does San Antonio count as subArctic?
I'm going to refer back to my Toronto days for winter reference.
If you're into the martial arts, any of the weapons training (especially short weapons, like jo, don'bons, tonfa or sai) will improve grip strength and dexterity. Even if you're not, a broom handle and some of the instructional videos can be a blast.
Snow-shoveling may not be enjoyable but it's a heck of a workout, especially when you carry the shovel full instead of trying to dwarf-toss it onto the pile.
Though the videos are good to study, I found that analyzing on paper hypothetical field layouts with an eye to opponent fire sharpened my sense of awareness to possible situations. You're not going to remember everything, but the exercise keeps you thinking about it.
For trigger time, I always use a mirror (yah yah, very funny) to watch my profile and try to decrease it. I liken this to those skiers who go into windtunnels and refine their shapes for least air resistance.
Oh, and sex. Also with mirrors.
Larry Janecka