Slides in for sure, don't ask why I say that. Oh never mind, I'll confess. I left mine out during a snow/ice storm and tried to depart the next morning - with lots of frozen stuff on the topper - very difficult to bring slide in - ended up going on roof and cleared the stuff off - not a good situation - the roof was so slick - dangerous. So, I don't leave them out anymnore - one time is a learning experience, after that it is "duh".
If you put your jacks down, they could freeze to the ground - again don't ask - lets just say experience talking. Use jack pads. I'm not sure by your post if you are parked somewhere or will be in transit -
protect your windshield wipers - cover them so they don't freeze to the glass.