I Have Not Rolled the 5" Refractor Out in Some Time

It has the advantage that you do not a ladder to get to the eyepiece and it is a spectacular apochromat. But once I was outside, I discovered the focuser would not move.  Not even a little.

Cold weather froze grease? Cold tightened a close tolerance too much? Were the screws that hold the rear plate to the focuser axle too tight?

No, simpler than that but only after I brought in back inside, removed it from the mount and started disassembly. Thus is a rock and pinion focuser and the rack along the tube had gone beyond the pinion.  I needed to gently pull the focuser tube out far enough for rack and pinion to mate.  I think i will epoxy a piece of plastic at the last slot in the rack that will prevent him from going too far in again.