If you rest it on blocks rather than on its tires you'll reduce the risk of flat spots setting in the rubber.

Insects and rodents might find you car a good place to spend the winter. Consider bait and/or poison as your conscience allows. I would try to lock the AC in recycle mode.

3-4 months is not a long time. My cars are usually off the road for that long for simple DIY maintenance

Sixto
91 300SE
81 300SD