If no one will be there you can drain the pipes and leave it unheated over the winter. People typically do this with summer homes.
(I think this thread is silly though: there's no way enough people will move to warm climates for the winter to make a dent in cold-country fuel consumption.)
At least in the UK, the part of the bill that is really increasing is the Standing Charge (a charge just for being connected to the gas network). So even if you turn off your heating your bills are still going to increase.
