Well, it sounds like your back, and not the weather, should be the real issue. I'd focus on whether you should ride at all until your back feels better.
I don't mind riding outside in the cold if the sun is out or mostly out and the wind isn't crazy. But I also have other activities--running, yoga, hiking--that I enjoy in the winter, so I don't struggle all that much with the ride inside/ride outside dilemma. I like the change of pace and activity that fall and winter bring. For every season, turn, turn, turn.....
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher