Are there any Winter Karting Series in the Northeast?

Well, they used to. But the indoor track that the New Hampshire Karting Association once ran some Winter events at closed down a few years back. So they are not doing that presently. I think they tried another place in Western MA, but nothing came of it.

Either way, the events there were not Wheel-2-Wheel races, but in a Time Trial format. The karts, even World Formulas, were too fast for that particular indoor track to have multiple karts racing each other at the same time.