Re: Your longest tow?
I have yet to find fishing so good as to tow 1900 Mi one way . Hopefully, you have ;-)
That said, I do a yearly trip to ME and/or NY every year that will log 1000-1400 mi on the trailer inside of a week. Never had an issue but I've always double checked everything (especially, lights, bearings and tires ) weeks before. Anything questionable gets replaced. IMHO, it's allot easier, cheaper and time efficient to do my maintenance /repairs in my driveway vs on the road. I also carry a spare tire, grease gun and basic tools. This year I treated the tires with Ride on sealer and flat protectant so feel that much more confident.
Good luck!
hth