You just found the best remedy, a torch. I use a propane one, my brother uses a pocket torch. He keeps one with him all winter. He uses it to thaw locks on his snow mobile trailer too. In fact, last time he went to the Tug Hill area, he brought a whole case of them with him, and sold them in 10 minutes.
generally before a storm i'll put a little oil on connectors. that usually takes care of promblem, or mount plow early. be careful not to scare storm away. my father used to say i'll go put the plow and chains on and scare the snow away.
WD40 ,starting fluid,brake cleaner,all do a nice job,the starting fluid and brake cleaner melt the ice but evaporate really quick. All of these also work great in the closed environment of a truck cab when left so that the nozzle bumps in to a solid item when stopping hard provides a plowing experience thats hard to beat.