H8PVMNT obviously knows his poop.
He has provided some really good information!
My 85 22R was at high elevation 9,500 feet and below, and sub 32d F temps many times.
At your elevation it's not uncommon for a 22R to act up at cold starts. The oil viscosity is a really noticeable issue at really cold temps... especially at very cold starts.
The only comment I can add at this point is a possible failed AAP diagphram. If it has a hole in it, it may not pump enough fuel into venturi to cold start the engine, and after it starts, it may cause hesitation at the throttle, or blubbering like the choke is on.
The spark is really critical to fire a rich mixture, so make sure the disty cap, rotor, spark plugs, and plug wires are fresh!
Gnarls.