Check the specs for the TV. There's virtually always some kind of information on this sort of thing with all the technical details about power consumption and what not.
My guess however, would be that if you have an LCD -- I'm guessing you meant LCD since AFAIK LED displays, which is a completely different technology, is still a few years off from being practical -- TV in such environments, it would likely be bad for it. The crystals could very well freeze, then expand, cracking the display and generally making a mess.
I would not make such a TV a permanent fixture in an RV.
I am wanting to purchase an LED HDTV, and am wondering what the minimun temperature is that an LED screen will tolerate. The TV is to be placed in a motorhome, that sometimes gets down to 30 below zero.