I've jammed 28's and fenders into 90's race bikes by using split fender brackets, which will solve your problem at the brake bridge and fork crown. I made my own by bending rear rack stays in a vice, but if i had to do it again I'd just order some from River City Bicycles.
You may have issues at the seat tube, I've solved this either by cutting the fender short so that it ends just above the closest point between the seat tube and tire, or by cutting a little window for the tire at this point, and keeping the normal attachment points. The first solution reduces coverage, subjecting your drivetrain and shoes to more tire spray, the second weakens the fender, which may or may not lead to it cracking, depending on fender material, how big a window you cut, and how har on the bike you are. If you get creative with zap straps and tubes you can make a very low-profile shield for the area where you lost coverage.
If you want to get funky with fenders, I suggest purchasing a Dremmel and developing buddhist monk level patience. Based on your pics, I see no reason why full fenders wouldn't fit that bike. It's just going to take some doing. I'd source some bolts with very low-profile heads, similar to a carriage bolt, to improve clearance inside the fender.
Smaller, less knobby tires, and less time on trails or snowpack will improve your chances of success. That being said, here's my setup, which never jammed in the snow:
