I live in NYC so for much of the winter it's impractical to work out outside. My solution has to been buy a few cheap pieces of equipment. With my sub-$500 home gym I can do pretty much anything.
Hopefully this weekend I will make a video showing some of the stuff that I bought and built and a few of the exercises I do to get stronger in the off-season.
It's mostly going to be low-rep and static hold training as my focus has been maximal strength for a while now.