Some expats may be intending to spend the entire winter here, others just a few weeks or months. But however long your stay, it is important that if you receive a UK benefit and are going abroad, even for just a short time, you notify the office that pays your benefit before you come back.
In fact any change in your circumstances, such as moving in with a partner, starting work, or even moving house, should be reported immediately to the relevant authority paying your benefit or pension.
Spending time out of the UK, whether for a holiday or to live, does not necessarily mean your benefits will be affected. But if you even come abroad for just a few weeks, failing to notify your local benefit office could be considered an offence and could lead to prosecution, imprisonment and even the confiscation of your home and possessions.
More information on UK benefits in general and on which ones can and cannot be received whilst living in Spain can be found at www.gov.uk.