Spain, particularly away from the main tourist areas on the east coast is a good bet just now. The south west, Jerez, Cadiz, Sevilla areas are all decent for rentals and the temp is good over the winter - Sevilla a bit cooler, Jerez & Cadiz 13-15c in January. Flights dirt cheap to Malaga, a couple of hours away but a bit pricier to Sevilla itself.
Its likely we'll be renting a house in the old quarter of Jerez this coming Winter, €400 per month for 160m2 townhouse with parking. Depends what you're looking for - houses with pools and gardens will be more expensive but, as usual, the further out you go the cheaper it becomes.
Portugal is also good for climate and day to day stuff, but rentals in decent areas tend to be a bit pricey. Decent places tend to go to locals first, leaving the dregs for foreigners - unless you're happy living in a semi deserted complex in the Algarve over the Winter.
Best advice, wherever you go, is to avoid the ex pat ghettos where all the foreigners live - an imbalance of foreigners/locals always drive prices up.
JF