Big-t-2538 once bubbled...
The < 40 deg. is only on the north side of the wall, and really only below 100ft. From what I understand, it never gets much above (if ever) 40 degrees at depth on the deep side.
I would anticipate temps in the mid 40s in the middle of Jan (maybe a little warmer), and no warmer than 40 to 42 by the tubes. When we were there in NOV, it was just under 50 at the surface (of course it was snowing and windy as hell that day), about 54 at 20 to 40 feet, and 48 to 50 out by the tubes (60ft.). Inside the plane (25ft), I got a reading of 51 on my computer on our second dive when we were inside playing with the toypedo for about 10 minutes.
As for the Dr. Pepper machine, that is one of my favorite things to play with at Gilboa...One day I want to get it lifted and move it around...just for fun...Brian and I have already thought of numerous places it would look cool at.