Do I ask to visit him?

So I’ve been talking to a guy for about 4 months, and he lives about 6 hours away from me but he came up to visit me at the start of October. When he left, I mentioned that I’d have to go to him next time, and he said he was all for that idea. The other day he mentioned it, saying that I could pick dates to see him and give him two weeks notice so he could give notice at work, but I said that it would be best if he chose the dates so it would suit him best, which he agreed with. That was a few days ago and he hasn’t mentioned it since. I would quite like to visit him over New Years but I feel like it might be a bit late for that.

Do I ask him if he still wants me to go? How do I bring it up?