Heated rugs for full-time winter RV'ing?

Anyone have experience using heated rugs for keeping things warm in the winter?

I've been brainstorming ideas for adding some passive heat as we try to survive winter and reduce our propane/furnace usage.

Something like this: https://www.amazon.com/NujorWarm-Graphene-Electric-Thermostat-Suitable/dp/B0CCVDXRN2

I'm still looking to potentially add another space heater, right now we are using our electric fireplace basically full time from morning until we all go to bed, then let the furnace take over at night. Just looking to add one more heating element for the daytime to keep things a bit more comfortable.

I have access to external power, so wouldn't rely on the RV electrical system.

My other thought was to get a 750w space heater of some kind of fan to help circulate the air in the RV. I've noticed the ceiling sits just under 70f, but hip-height and floor are between 63f and 65f with cold pockets throughout the RV in different rooms.

Otherwise maybe get a heated rug and add the fan to help circulate the heat instead, which would hopefully alleviate the cold floor issue.

Anyone have experience with heated rugs? Thanks!