I finished half my basement a year ago, I also live in new England. I bought 5 gallons of drylok first and put two coats on the wall and floor. Then put 2in foam boards against the wall and use tape in between each foam board. I framed right that right after. I just had to be mindful of leaving enough space for plumbers to access any drain pipes, so I had to make an adjustment on one corner. I've had no issues with water at all since completing it and it stays pretty warm in the winter even without the baseboards on.