I think some are more affected than others by the weather. I'd just make sure that your horse has plenty of water of a reasonable temperature available (some don't like very cold water), and blanket or shelter them appropriately.
If they play and run in the snow, safe to say they are enjoying the weather more than you.
I actually had a horse suffer a mild colic on Monday. I have had two mild colics just this past Dec/Jan and I've never had an issues before. Both were solved quite quickly with a some banamine.
Monday I blamed it on the moon phenomenon.
This weather is whacked--and it does effect them.
I don't think it will be as bad as everyone is predicting. It will be in the 40s tomorrow.
Lately, my guys are getting a little bit of beet pulp with their water for dinner. Takes them longer to eat that way also because they spend a lot of time slurping.