You know you can use aircon for warm air too?I would also check the pollen filter, I have found a few strategically placed 10g+ silica gel pouches also help absorb moisture in winter.
Anyone know exactly what fuses and relays are for the air con? I've looked in the owners book and it doesn't list anything other than 'blower' for which it lists two, although my car seems to only have one of those fitted?!