My 2 cents is that the thicker oils, gear oil mostly, is the biggest culprit (besides the gas).

My mechanic buddy (19 years as a mechanic) said he`s pulled diff covers off vehicles that had been driven and warmed up.... and the fluid inside rolled out like molasses.
Full synthetic gear oil is a must.... again - my opinion.

I also run semi-synthetic engine oil but I think I may switch to full synthetic pretty soon.

^ that does make sense. Colder it is, less freely it will flow. Making it less of a lubricant so to speak.

I agree, but once your engine gets up to temp that oil should be hot and runny.

True.

Good point.... my main concern is the lack of oil until it does warm up.... just wonder how much damage occurs on cold startups... I'm thinking the semi-synthetic is probably good enough... I don't know, just rambling now... lol.

Well, I don't know much about the northern winters, but I do know if you live far enough north, you should have some heating devices. Block heaters, oil pan heaters, etc... I remember reading about something called an arctic leash once... don't remember what it is now though.