The new snow finally tapered off today not long after 5. So I got my boots and cag on and went outside to fire up the snowblower to clear the driveway. Again.
Refueled snowblower. Started snowblower. Brought throttle up, cut back choke, engaged auger drive. Snowblower died like it had been poleaxed.
Huh. Must have engaged the drive too suddenly on a cold engine.
Restarted snowblower. Engaged auger drive, more gently. Snowblower died.
Examined auger. Found a bunch of semi-thawed-and-refrozen icy slush blocking the impeller barrel. Cleared it out and made sure impeller turns.
Restarted snowblower. Carefully began to engaged auger drive. Snowblower bogged, clearly about to die.
Shut off snowblower. Examined auger again. Found a bunch of ice frozen around the auger spur drive box that looked like it might be locking up the auger. Broke away the ice. Made sure I could turn the auger at least slightly.
Restarted snowblower. Carefully began to engaged auger drive. Smoke began to come from under drive belt cover.
Stopped snowblower. Sent upstairs for socket set. Removed belt cover.¹
Restarted snowblower. Auger immediately began to spin, even though drive lever was disengaged, spitting a wad of snow out the chute.
Hmm. That's funny. Maybe the auger drive tension roller stuck in engagement on the last try. Gently begin to engage drive to see if I can unstick the roller. Auger drive belt snaps.
 This would be the belt cover that I had to modify because there was insufficient clearance under the PVC drive belt cover for the belts², causing the auger drive belt to rub on the cover when the drive is disengaged. (Yes, when "disengaged", the belt is actually still being driven by the driveshaft sufficiently to wear away the belt cover and heat it via friction to the point of smoking and partially melting.)
 Yes, in case you were wondering, this MTD snowblower IS a piece of junk. But it was free.