I pull my prostar to Northwest Ontario from Chicago every year - 1500 mile round trip.
Before I leave I inspect bearings and the the bearing buddies a refill of grease - I use marine synthetic grease, then inspect tires.
I stop every 90 minutes and check tires and hubs for excessive heat... on first 90 minute inspect I check rear of wheel for grease spatter in case seal fails.
I also watch the trailer like a hawk - looking for any smoke or tire wobble or bounce.
I also carry a spare set of bearings, seals and races... not a tough job if there's a failure on the rode....IMO..
...A bad day water skiing still beats a good day at work...1995 Pro Star 205....