If you bring the plant indoors, the snake may slow down some because of fewer daylight hours. You can't count on it hibernating because of the warmth in the house. I'd figure out a way to get him out first, and then bring the pot in. Maybe a serious overwatering of the plant. I'd put the hose on the plant and then go indoors and watch for him to emerge. If he sees you, he may do all he can to stay with the plant. When he leaves the plant, make a dash for it and put it in a place where he can't get to it and let it drain.

I treat all my indoor/outdoor plants before I bring them inside. Here's how I do it: Find a bucket large enough to submerge the entire pot to the rim. Fill it with water and add a few drops of liquid dish detergent (hand washing kind, not dishwasher detergent.) Put the pot in it and let it sit for half an hour or more. Scoop out any critters that have floated to the top, take the pot out, spray the foliage with a strong stream of water, and let it drain. So far I've never brought in any critters by using this method.

It's most likely a Dekay's Brown Snake (a small harmless terrestrial snake) from the description. I agree with ccox that it probably wouldn't hibernate in the house both because the temperature will be warm indoors and because a flower pot probably isn't a fully adequate hibernaculum (overwintering den) even for a little brown snake. It will start to make a line for its den soon if it hasn't already. Given that you saw the snake burrow for cover in the summer, I think it is fairly likely that the snake is no longer in the pot. Chances are pretty good that it has already moved on toward its overwintering den and is no longer in the pot.