A.F.
I know what you mean! I wanted to save -everything- from my first. (and we weren't even planing on ever having another one) But it's a good thing I did hang on to stuff. To store stuff like strollers, I just used those big heavy duty trash bags. I put the stroller into one and put another over the top and taped them both together. Since they were heavy duty, I didn't have any problems with it taring. Sheets and the like will do well too. Take apart anything and everything that you can to try to save room. Boxes do work nice too as they stack very well. :) Anything that I couldn't keep, I sold to one of those baby resell shops and saved the money, or gave to friends. Which I just got back anyways because I found out I was pregnant and they weren't anymore. lol!
Hope this helps! Good luck! :D