How to stay loose in winter (where its actually cold)?

You said it yourself, you need to put in the time, but would prefer to ski instead, it's all about dedication.  If you want to stay in form, then get out and practice.  I've been on a strict 3 times per week routine in the winter for practicing. 

I go to the golf dome all winter long.  Its not perfect as its only a 100-yard long range but its better than putting my golf game on the shelf all winter long and trying to shake the rust off in March.

Generally speaking, if the golf course doesn't have snow on it....I'm playing golf.   That's how I stay loose. 

I have the Optishot golf simulator. I set it up in my 12w x 12w x 16h barn style shed. I don't hit anything longer than 4 hybrid because of the way I installed the lofts and shelving but it keeps me loose on rainy and cold days and warms me up when the course I am going to has no driving range. I repeat, it is great for keeping you loose and grooving your swing. It is not a true launch monitor and you can play several golf courses on it. I enjoy it a lot. It has helped my hit lower scores on the golf course and has lowered my handicap 2 strokes so far. Good Luck.

It never hurts to work on your swing in slow motion indoors without hitting balls.  I get antsy in the house and do the pump drill at least 50 times a day to make sure my upper and lower body are staying in rhythm. 
 

Im actually fairly close, I live in Portland and tend to try to golf at my local course (http://www.pumpkinridge.com) whenever I can during the winter. Though obviously it's much harder to go when it starts to snow so thats when I switch over to practicing my swing at home to try to keep in rhythm.

I joined a local golf simulator. 20 something HD versions of famous courses, plus a fully stocked bar and food. Not the same as being out on the grass but it's warm and close by! It was great to hit the ground running last spring.

If there is no snow and it's windy I play which I think is the easiest way to keep your game up all winter. If you don't have that option I'd probably look for a heated range or just swing the club in my backyard.

 

Hey, I'm not too far from you, just across the border; will be playing North Bellingham tomorrow.

 

Stretch the Hips man, do a quick walk around the block to warm up and then attack those hips. I stretch the hips 2X per day. Find the Youtube vids for titleist fitness, you'll find some great stretching routines!!