Hi there! That's great that you're looking to spend the winter in Spain. Have you been to Valencia and Cartegena yet? If not, both are lovely options and quite different.
Valencia is Spain's 3rd large city (population about 800,000) with a lot of culture, restuarants, arts, and entertainment, as well as mild winters, although lows can get into the 40s and highs are in the 60s.
Cartagena is very lovely, however, a much different lifestyle than Valencia. It's a smaller city (around 200,000) and will be more laid back, and has much less going on. However, there is lots to see in and around the city.
Spain has a wonderful public and private healthare system. Your wife being Italian, she may be able to get on a EHIC: https://employment-social-affairs.ec.europa.eu/policies-and-activities/moving-working-europe/eu-social-security-coordination/european-health-insurance-card/how-use-card/spain-european-health-insurance-card_en
Let us know if you have any questions!
Cepee, IL Correspondent - Spain