I had my FR remapped with Upsolute at around 12k miles. Month or so into having it done, clutch was slipping in 4th upwards and not long after, 3rd was also affected. 5th and 6th acceleration was a joke as even a light dab of throttle causes slipping.
Contacted Simon Coe who did the remap, he told me maybe 1 in 10 VAG cars he deals with have clutch issues with remapping and can usually be sourced to faulty clutch components.
He suggested i try getting a new clutch under warranty, and so reset the car to standard (to avoid warranty issues). Sure enough, the clutch slipped still, albeit not as much. Took it to SEAT, where they replaced the clutch, cylinders and release bearing with no questions asked (well, after a quick test drive to prove it slipped). Surprisingly good service.
Had the remap back on about a year now, it's never slipped once, and am at 26k miles.
Cold weather does increase the chance of slipping (more torque produced)...
It is annoying when it does slip though, relaly hampers driving enjoyment.