aux power hookup?

hi!
im currently on a road trip with about 9200miles in. i started in chicago and im currently in fairbanks alaska
ive done alot of car camping since i left in early sep and love my prius. it roomy enough for me and all the crap needed for a 6month journey.
however as i sit here tonight using holiday's inn internet i looked to my left and saw three mid size pickup trucks with male ended power cords coming out the front end. one of these trucks looks kinda old so it got me thinking.
has anyone heard of a mod to add an auxilary power INPUT. i love how the prius will pump out heat and start the engine when needed. but is there anyway to add a plug so that it can run the heat, and not have to run the gas engine to charge the battery (because the car would be plugged in). basically making it like a rv with full hookup.

i will do my best to respond to any question but please give me time. alaska and northern bc/yukon are not known for there wifi hotspots. ill do my best though to check tomorrow.

thanks in advance for any responses. i searched on the subject but didnt find much. all i did find was ways to mod the 2k5 prius by adding a battery and making it more like the volt where it runs off of that for some time before using gas but thats not what i want. and the solution is in the thousands because you need to buy the different type of battery and have it installed.

 

thanks for the replies
i think i might go with the small space heater because just using the electric seems to use alot less gas. without heat on the engine only starts up once every 10mins or so but with the heat on its like every 3-5mins. and it sucks because the a/c auto doesnt really work for heating

after doing some research around fairbanks i found this is called "winterization"
but no one could really answer my question about what im trying todo. which leads me to the quote below
"It's not a general power input like your desctiption though"
i think what ur saying here is that the power plug goes to the normal battery not the electric engine battery (if that makes sense)
so basically there are 2 batteries in hybrids and the one that the plug goes to is not the same one used to run heat when its idling

but i couldnt get a clear cut answer on this