For a four-person sleigh, you're looking at a draft horse- light breeds are going to have trouble pulling anything that heavy on runners, through snow. A lighter horse could handle a two-person sleigh. But since winter is only one season and you want a horse for things you'll be doing a lot more of the time (trails, carriage driving, etc), I would focus on that rather than trying to hit all your wants right off the bat.
To start, I'll say that the best breed is "broke" and "gentle", which can come from MANY breeds and types of horse. When you search, look at individuals rather than breeds. If an Appaloosa, Thoroughbred, Saddlebred, Arabian, or a Heinz 57 mutt, whatever comes across your path that is gentle, willing, and SAFE, that's the horse you want. I would take refresher lessons with both riding and driving instructors before you start shopping, and take someone with you when you go to look at a horse. A mistake buying a riding horse can hurt you, a mistake buying a driving horse is force of mass destruction set loose.
A standardbred would suit most of those purposes just fine, and there are MANY of them out there that have already been retrained from being off the track and can be adopted through various organizations. Most of them are also fantastic horses who are very well-suited for trail horses and general riding horses due to their training at the track -they're used to noise, fuss, traffic, being loaded and unloaded off trailers, being bathed and groomed, hitched and unhitched, and lord knows what else, pretty much from the day they hit the ground.
Get to know the driving and riding community where you will be living, and talk to a lot of people- that's the best way to find what you want!