1- Clipping the wire together should work temporarily
2- yes, you can replace it in less than 5 minutes
3- If you peel off the black foam that says ECO/T-STAT you will see the thermostat. Unplug the wires and turn the plastic washer until the slots line up with the metal tabs, pull it out, and reverse the procedure to install the new one. Don't get the t-stat and ECO mixed up. They look the same but they are a little different.
4- Most rv dealers should stock them, or you can order them online. They will come in a pack with the t-stat and ECO and a new foam cover. Should be $20-$25.
Mike & Roz
2018 Grand Design 315RLTS
2013 Ford F-350 Lariat PSD/CC/LB/FX4
Sunlines= '06-2075, '06-264SR