cold always messes with small air cooled. I run "heet" in the gas, def helps. When charging just about done rpms so low engine producing no heat when it's cold. I can take plug out and hold it tightly, can only feel the slightest warmth. Dry black soot covered. Not running hot enough. Looked at manual, said replace plugs every 100 hrs, lol, all my plugs have at least 1000. So, got new plugs, it helped. On the 2000 carb there is an air screw, turns 1/4. When it hits 0 I squeeze off some air. As it gets colder I duct tape the front intake vents and cover with a sleeping bag. -30 and I tape the side vents as well and keep covered up. Runs good @-55f. Took me years to figure out how to keep em running deep cold.the EU 3000, starting get tired...getting some blow by, the carburetors getting iced up pretty fast. I'm not fixing it lol. Just chasing it around. These things show up when its cold don't they.
In your environment I image condensation in gas tank and jerry jugs would be a prob