Good luck with the transplants.

I agree with Mary - go through the big stuff that you can see, clear out what you can there first. If it is a matter of navigating through papers out on flat surfaces, get a few boxes and box them up until you can go through them properly, but they'll be up and out of harms way, and out of your way, until you can file. (The alternative being, if you decide in the future that none of the papers is worth the trouble, you can send the boxes to be shredded).