Tips for long trip with travel trailer?

I would advise to find a campground for the night rather than a parking lot, because of the kids. The will need some down time from the drive, room for activity and bathrooms. Plan your route and find some close campgrounds. Alternatively, do what we did last week - on the way to Michigan for a rally we stopped halfway at a Red Roof Inn, which was only $50 for the night. Our dog loves RRI, and we didn't have to worry about any set-up, clean-up and just got back in the car in the morning and were on our way. Trip home was in one day, 8 hours.