Retracting Slide in Winter Wonderland

I would leave it out rather than pull all that ice through the seals and into the trailer.

I trust you are not in a hurry to move the RV. I would try to cover the slide with a tarp of some sort. Pick a decent day and put heat under the tarp. Don't catch the thing on fire.

Same thing happened to us over the weekend and we were 80 miles away from home. I used heat inside, a broom to get all the loose snow off, a hair dryer and the sun to melt, and a plastic scraper to clear it off. Becareful if you are on the snow covered roof. It is slippery and you can't see the skylights or vents. A tall ladder is best, but of course I didn't have one with me!

I had a trailer with a slide and got caught in the snow during a fishing trip. The snow melted during the day and then froze into a good sized chunk of ice at night. When we were going to leave I couldn't get the slide in AND couldn't get to a place where I could remove it. It was a mess. By the time we finagled a fix, the slide came in and during the trip home the snow/ice melted and made a real mess inside. Also had other trips during heavy rain storms that created similar messes inside along with issues trying to get the slide out on a couple of other trips. Needless to say, I don't have a slide anymore.

If there is a chance of warmer weather coming you can heat the inside of the trailer and wait until the snow melts. By the look of the forecasts that might not happen anytime soon. I would get up with a ladder and remove as much as I could. When retracted the snow will melt off but if you are ready with towels it shouldn't be a big thing.

Good luck.

You have only two options:
More heat
More time
Ice WILL damage your seals and melt inside.
If you're really worried you could use a hairdryer or a heat gun and a sponge
Good luck,
Mike