You must be from North Dakota or Manitoba!!

Lightly lubing the door seals will keep them soft and also from sticking/freezing. As for the internal door parts, I'm not a fan of spraying stuff in there as most lubes/coatings attract dirt/dust over time. IMO, a hair dryer and a couple minutes of your time is the best way to keep the locks & handles from freezing. I've Been doin it since the first winter with the X, and 7/8 years later have yet to freeze myself out!

We're no stranger to temps below -30*C here in Winnipeg...we know COLD!! Lol.

The TEFLON (at least in the Tri-Flow) appears to be a factor in preventing build up of dirt/dust...unlike using some lubricants or oils that don't have TEFLON.

The PTFE (polytetrafluoroethylene) aka "TEFLON" helps prevent build up of grime/dirt/dust...and if you use it annually in a winterizing ritual...the new application usually disperses any build up. And due to its properties...
Tri-Flow is used (and sold a lot) in biking due to how well it lubricates bike chains without causing build up of grime between the links etc. Other properties of TEFLON include:

• hydrophobic: neither water nor water-containing substances wet PTFE
• reduces friction, wear, and energy consumption on moving parts or sliding action of parts against each other

This is not to say that other products don't work as well (or even better)...but these 2 products I have found do well for the winter environment of the lower Great Lakes region. :)

i live in northern ontario sometimes we get -40`s with windchill