I had to rollback to an older wifi driver to fix mine.
which old driver did you roll back to. The original before the day one update or the one from the surface 2?
I haven't had any lock-ups, What happens if you disable Webroot A/V?
I had random limited connection issues with the WiFi. I uninstalled the wireless card drivers from device manager (I also selected delete the driver software for the device) then scanned for new hardware to load the original drivers. No WiFi issues since. After installing the old drivers I received an update for Windows. Running the update loaded the new drivers again so watch for that. The update is called System Firmware Update - 6/19/2014