Are they opened in late January

If I recall correctly that's a no. If it's too cold I believe they give the horses time off from trail rides. I recommend giving them a call though they are really friendly and informative.

I have no idea, I went about a month ago but I'm clueless about their winter schedule. Once you factor in the possible snow and ice going horseback up and down a mountain, I would guess no. But contact them to be sure.