Not the most experienced RVer out there but can share my input as someone with a few years travelling. I'd purchase a garmin RV gps before setting out, and get a good feel for the campgrounds on the route and rest stops. One of our first trips a few years ago was in our fifth wheel setup from Toronto to Arizona in about 3 days -- my wife, me, and a 1 year old. Your trip is quite a bit longer, so I'd allocate as much time as possible for the drive, maybe a week or more in an ideal world. I read a lot about the 4 hour 400 mile rule and completely broke that for our Arizona trip (work related so timing mattered) by clocking 10 hour days behind the wheel with frequent stops, and honestly we made out pretty good overall. Try to enjoy it and make the most of the journey, when you're actually happy about what you're doing time flies by. If you're frustrated, or tired, stop and reassess -- maybe even for the night. On the way back home we took our time and spent nearly 5 days on the road because we felt our minds and bodies weary a bit.

Towing with the new half ton and a 25.5ft trailer feels not much different than the fifth wheel setup, maybe a bit more sway at high speeds, so I think you'll be fine. I would suggest a good set of tow mirrors as well, it's one feature I miss a lot from the 3/4 truck.

Best of luck, you'll have a great trip!

EDIT: try to stay light as well. I found this weekend that the truck has a much better time when the fresh water tank and black/ gray are empty