First, do not put volatile inflammable substances inside a normal refrigerator as there is a very good chance you will get an explosion. As an example (my recollection, going back 30 years) some rats which had been euthanized with ether in the university where I worked were inside a plastic bag in a normal fridge. In the early hours of the morning there a spark from the internal thermostat exploded the fridge and set fire to the lab, burning it out. Sufficient ether had diffused from the bag to form an explosive mixture in the fridge. Following that, all lab fridges were fitted with external thermostats and marked as "safe".
Personally, I use drmoishe-pippik's 2nd suggestion when I'm cleaning paint brushes by putting the brush, in its container of solvent, inside a tin with a press-in lid (I don't use a plastic container as many solvents will permeate through plastic). I use the same approach with small containers of glue and in both cases, there is greatly reduced evaporation. This is the approach I would recommend for your acetone and IPA bottles.