I haven't read your scenarios but the specifics besides time to darkness are really important: what season, what is the ambient temperature, is it raining or snowing, how wet are you, what terrain are you in, is your car or canoe still accessible to you? Alaska in winter is far different than the Boundary Waters in summer. Cars are qualitatively a much better shelter for a wet person than no shelter or even a canoe.

Taking out the extremes, I would first stop and assess my situation - what kind of shelter do I have, how wet am I, do I have any other clothes to change into that aren't wet? Can I set up a signal that would attract rescuers in the time before darkness?

If I'm irrevocably wet, I would plan on staying up all night, focusing on not getting any wetter, and trying to stay away from hypothermia. Walking, pacing, jumping jacks. If its raining or snowing, I would focus on shelter - my car or an upturned canoe for starters. Either will keep me directly out of the elements and trap a fair amount of heat, although either will also make a nice coffin in the wrong circumstances. I would gather whatever ground cover I can such as tree branches for insulation under me and over me, and wait the night out. During the night I might have to trade some time out in the wet and cold for time getting my engine (internal heat) running again. I would eat a fair amount of my food rations to ensure I could keep my engine running through the first cold night - assuming I survive, I can focus on drying out and warming up during the next day, and reduce my rations for the amount of time I expect to be lost. Given any adverse circumstances where there is a deficiency in my clothing/insulation or I keep getting cold and wet, I would focus on staying awake to stay alive that first night, and continue to improvise to improve my shelter or my degree of wetness. If I die, I can sleep then.

In reality I carry overnight preps with me on any excursions, but I assume in your scenario those get dumped in the water or lost along the way. If I'm lucky I'll find a cedar tree, which have enough needles underneath and cover from rain above to afford me a chance at surviving a fairly cold night, with maybe some sleep. Or again, a nice final resting spot if the weather doesn't hold.