Not sure it has anything to do with colder or warmer temps, unless itís freezing then thawing. If youíre parked on a hill, water that is trickling out from a certain point can and will run along a frame rail, wiring, tubing or anything else before dropping to the ground, this can significantly throw off the actual point of exit. Make sure you are parked on a level surface to determine where the actual leak is.
When you turn on the pump, without opening any faucets, does the pump cycle on/off?
If it does, it indicates youíve either got a broken or cracked line allowing air into the closed pressurized loop or youíve got a valve or the small drain line open or worse case, your water tank is cracked. No visible signs of water inside?
Also check the back of the city fill connection, the plastic fitting where the water line attaches to can crack, sometimes hard to see.
If you turn on the pump and it cycles on/off with all faucets closed and tank full, you will more easily see where the water is exiting from. Get underneath with a good flashlight.
Iíd suggest you keep trying to find that little T-handle drain line and see if itís completely closed. This is hopefully the culprit
Looks like thisÖ..