A couple I know has recently built a new house about thirty miles from the city that is "completely" of the grid. All of their electricity comes from solar, with a small boost from wind. (Oddly enough, even Saskatchewan isn't windy enough to provide a reliable power source by itself.) The only phones they have are cellular and their Internet access is also wireless.
They are quite close to a natural gas line but it would have cost thousands to bring it a few hundred yards to the house, so they use propane for heat - with radiant floor heating.
They've been in the house for two winters with no serious problems that I know of.