TFs in the attic...

Space has become quite the valuable commodity at my home lately. Another family member will be moving in with us for a while (a year, most likely), and some of my packed up TFs will need to move to make some space. Does anyone here need to keep their TFs in an unfinished attic? It's dry and dark, but the temps up there get pretty crazy from season to season, even with ventilation... I would be storing basically the Beast Wars through Cybertron line (BW, BM, RID, ARM, ENG, CYB), if that matters as well--no G1, Classics, MPs or Alts up there, that's for sure.
All of these TFs are currently in sealed plastic tubs--not ideal, but free from exposure, anyway.
Any advice, warnings, suggestions, etc. would be appreciated!
Any sympathy is also welcome.
Thanks in advance!

Any advice, warnings, suggestions, etc. would be appreciated!
Any sympathy is also welcome.
Thanks in advance!