Just an example:
Say you have 4 people (600 lbs), 2 dogs (100 lbs), and your WDH (100 lbs). You take your 1350 lbs and subtract that 800 lbs and you are left with 550 lbs for tongue weight.
The more stuff you put in the TV the less TW you can handle. TW is typically 12-15% of the loaded weight of the travel trailer. Dry weights are usually meaningless unless you read them from the sticker on the trailer itself. Figure folks usually add 1000 lbs of stuff to their trailer. So a TT with a sticker weight of 4000 lbs could weight 5000 lbs loaded. That would put the TW between 600-750 lbs typically.
Remember this is all just theoretical as different trailers have different distributions and behavior characteristics going down the road.
Now this could be a moot point if your receiver is only rated to handle 500 lbs, so that's important to know too.
2016 Chevy Silverado 2500 CC LB 6.0L
1998 Chevy C2500 Suburban 454 3.73 (Sold)
2012 Ford F-150 EB CC 4x4 w/Max Tow (Sold) 😞
2013 North Trail 28BRS