Hello TexasPride22 - one thing that you have not said is what part of Texas you are talking about living in. It will make a difference in your winter prep situation. I have been living in my trailer in SE New Mexico for the past 4 years and being prepared is what counts.
As has been said, running a supplemental electric heater will help when temps are milder, but you will need to run the furnace to add heat below when it gets freezing. Also consider adding heat to you water hose or running off of the tank. Another thing that got me once was my sewer hose had a slight dip which remained full of grey water and then froze plugging up the hose. Had to work hard to get that sorted out so that I could dump my tanks.
For your propane cost - the $70 number is extremely high. Here I have been paying $20 for a 30lb fill for the past year or so. Never paid more than about $30.
Good luck, keep coming back here with questions and people will help.
