I have the same: 4" PVC molded, about an inch high. My cave was in the high 50's for the first stage, then I took them out of the cave into the room which was then kept in the 40's, but recently dipped into the high 30's for a couple weeks.
On another section of the forums I asked about possible problems of too-cold aging. They never froze, so I assume there is dormancy perhaps, but nothing bad.
I'd like to have mine a little saggy in the meat of the cheese. The first cam I made went 11 weeks and was nice, but still firm. It had quite an ammonia smell in the shell, though. Not a bad cheese, aside from too much salt (reapplied outside due to cat's hair): great texture, proper shell, proper odor, just too salty-what was behind the salt was good. My second batch of cam was swamped by a lime green monster mold, and those turned into stinky crap (the mold was from too much moisture in the cave). This, my third try, looks right, so I'll let them slide through to very ripe condition... if I can.