Actually the Schefflera and Peace Lily will survive pretty cold temperatures. I have numerous of those (along with Jade and Rubber Trees) that have survived mid to low 30's. However they were all under oak/cedar trees and thus were protected from frost. I have lost many of these plants when the temperature dipped well below 30 F though. That being said, because of the other plants involved, I would still maintain at least the 50 F.