I agree with what’s been mentioned above.
This is my third winter of every day driving and this is what comes to my mind so far.
Hopper juice: Removable tank is a must in extreme cold conditions unless it’s kept very close to hot parts and emptied within a couple hours after a drive. However the juice seems to keep liquid down to -6 or -7C.
Cooler condensate: With high enough in- and outlets you can usually wait for the next thaw or until you make a trip long enough to let the woodgas melt a block of ice. Mounting the tank prior to the cooler helps but a downstream filter container will still collect water/ice.
Plumbing: For some reason low spots in the pvc plumbing up to the motor haven’t caused me any trouble so far, but avoiding them won’t hurt.
Torching: See to that critical parts like hopper drain, hopper lid seal, drain valves, woodgas valves or any other moving parts can be easily reached with a torch.