Are you concerned mostly about the car being parked over night or while at classes?? My TDI(s) get inside an unheated garage over night but when I used to commute to work it sat out on the street 10 hrs where it was very cold in the winter (I live about 50 miles from you). Severely cold days I would start it after lunch time and let it run for 20 minutes or so. Even in -30F with the cabin heat blower OFF, radiator covered with coroplast it will warm up the coolant almost to 190 and starts like warm weather when time to go home.
If you have access to plug in power when parked overnight a FrostHeater type coolant heater on a timer makes for warmth almost right after start up.
The proper size battery, working GPs, proper advanced injection timing and (often overlooked) a new or refurbished starter make for much better cold weather starting. Most of the aging fleet of TDIs can benefit from a new starter. Cranking rpm is gradually unnoticed and lost over time.
If you don't have or need VCDS to check timing/etc, drop me a message and we can get it checked out sometime when on a school break.