It's only going to be as good as the weakest link in this food-chain and that will
be the connector between the TV & trailer
I'd get a NEMA 4 junction box with a 30amp minimum terminal block mounted on the
inside. That TB needs to have 'U' jumpers to tie several terminals to become the
hot and ground...plus the control lines for the rest of the trailer
Then from that point you can decide spider (wagon wheel with it the hub and the
points the spokes) or one big lead 'back' there
Make sure to use ring lugs and NOT spade lugs.
If you don't have lots of experience crimping lugs...practice, practice...
Suggest buying your connectors in large, contractor quantities. Especially
if you are going to be working on your own stuff. I also buy'm on sale
so the per connector cost many times is less than half of list.
Here is one of my electrical setups when doing the harness for my
Suburban
I no longer own a trailer, but borrow often. Some allow me to update
their's when I've decided going to borrow often.
I use a #10 AWG with a ring lug to their trailer end of the connector
Then run one #10 AWG wire 'back' there and then split it to both sides.
Since not mine and they won't pay for the install...just a 'thank you'
I don't put a NEMA 4 box back there. Just water proof the splice