We camp alot off the power gird and it was better for us to install a PURE SINE WAVE 600WATT POWER INVERTER ($159 AMAZON) to use.
12VDC TV's are very pricy and the VIZIO 120VAC are availabe from WALMART everywhere. We have the 22 Inch HDTV in our OFF-ROAD POPU setup... They are very reasonable cost wise and on sale alot...
The POWER INVERTER allows us the option of having 120VAC available for all kinds of low wattage 120VAC items...
I have many needs for alot of items and normally only use around 300WATT of Pure Sinewave power when camping off the power grid. Having the additonal 120VAC from the POWER INVERTER is a good deal for our style of camping off the power grid.
In my case I ran two 120VAC drops from the POWER INVERTER and have two dedicated 120VAC receptacles just for emergency power. One at the home entertainment location and the other one near the bed area...
We leave our home entertainment on the POWER INVERTER all the time even when we are using 120VAC from campground hookups...
This is what we ended up doing for camping off the power gird...
Roy Ken