"At times, I can [be] gone for weeks at a time and.."
OK.,,, I understand your concern then. I myself, have been able to tend to my bees [1-4 colonies

] for weeks at a time when it might be important to do so; and not be absent. Except for this summer because of sugery but I timed that about right.
Yes, the weather can be quite harsh for the bees. Last year the Silver maple bloomed and the weather was nice [55-65 degrees F.] for about one day, as I remember,....and then it turned cold for a week+. But, I don't think many WI. beekeepers then rush out, and put pollen sub on as an 'emergency'.
The fondant is fine and you can add a pollen sub patty if you want to.