hi markus,
the winter here is difficult. all bars which stay open during winter are lucky enough if they have enough business so that the owner can survive. employing staff is impossible.
i have ventured out a number of times this winter and have never seen more than 20 people at any one time in any bar - this includes pacha at the moment (not at xmas though).
if you are interested in staying the winter, you either have to earn enough money in summer to tide you over or look to get a 'proper' job. for 'proper' i mean anything non-tourist related. for this you'll need spanish.
dossing a winter here used to be a wonderful way of chilling after the summer, but since the euro came in, the prices have increased to such an extent that working is a necessity.
that sounds a bit depressing i know. if you are lucky enough to find work which pays throughout the winter, there is no finer place in europe - we've had days with weather to die for and walking salinas beach in a t-shirt in the middle of january with not a soul in sight just has to be experienced ;-)