I have run into LOTS of problems with the Intel WiFi chip set on Surface's.
I would disable power saving on the WiFi NIC with these commands to save yourself a lot of grief:
powercfg /SETDCVALUEINDEX SCHEME_CURRENT 19cbb8fa-5279-450e-9fac-8a3d5fedd0c1 12bbebe6-58d6-4636-95bb-3217ef867c1a 0
powercfg /SETACVALUEINDEX SCHEME_CURRENT 19cbb8fa-5279-450e-9fac-8a3d5fedd0c1 12bbebe6-58d6-4636-95bb-3217ef867c1a 0