It depends as we don't know if the underbelly is exposed or not, plus there is no definitive answer as to what minimum temps you plan to expose your TH to. Our TH has an exposed underbelly and we often camp in the 20s overnight with daytime temps in the 40s, it has to be below freezing for an extended period for our TH tanks to freeze.
Have been caught off guard several times with overnight temps dropping to around 10 degrees, but a couple hours after sunrise all was back to normal, that may not be the case for every rig, one should tread lightly before exposing their rig to these temps.