I don't even worry about it. I have found that if I bump up the salt level a bit it tricks my non temp compensated Goldline unit into producing chlorine better at low temps. If it gets cold enough to shut everything down not much is going to be growing and we aren't using the pool. I live in N. Fl so we always have sun but it has not grown any algae in the two winters the SWG has been on line.
Bottom line is if it does develop any problems it's nothing a few jugs of bleach would't take care of!