I am 6' 2" and ride a 60 cm LHT. Unless you do something out of the ordinary, you will be in a more upright position than you probably would be on a road frame, but you won't be sitting straight up. My bars are a hair above my saddle and the ride feels perfectly balanced. Not too much weight on the hands or the rear.On the upright vs more aggressive riding position...
As for the age-old debate about panniers vs. a trailer, there is no correct side.
Some considerations assuming, for the sake of discussion, a B.O.B./B.O.B.-style trailer:
If you take your bag(g) inside the tent, you have one bag with the trailer, more (usually 4) with panniers.
The trailer can make it easier to make a grocery or firewood run using the bike. No need to make space in your bag or panniers. During our group x-country tour we found a trailer extremely useful for carrying 30-paks back to camp from the store.
Without a trailer, there is one less item that might have to be boxed and shipped or might cost you an oversized baggage fee.
Less wind resistance with a trailer. However, you don't have panniers to act like sails when you have a strong tailwind.
Some have trouble sometimes fiding parking space for and/or turning the longer bike-trailer rig.
If your tariler bag isn't compartmentalized. you may want/have to do a little more organizational work, such as keeping things in ditty bags or individual stuff sacks. My panniers have adjutables "walls" inside the main compartments that allow me to create segregated spaces if I want to. I happen to like that since, by nature, I am generally a disorganized person when it comes to physical items.
Lots of room for personal preference there. My sweet spot comfort wise is with the bars 4-5" below the saddle (very close to what my road bike is). I find that most of my weight is carried on my legs with very little is on my hands. The key is a nice relaxed upper body, elbows bent, shoulders relaxed, etc. Even on the longest days and with multiple months on the road I find that works best for me. If a more upright posture works for someone else that is great. I just don't get the notion that some seem to have that the more upright the posture the more comfortable.
Nice evaluation on the trailer issue. I'll add a couple other issues for consideration...
If you tend to ride with others the ability to draft is greatly hindered by using a trailer. It may be a big deal for some and a non-issue for others.
There is another size of tube to carry spares for (or even another size spare tire for those who carry spare tires).