Well retired people like me with no time pressure aim for 300 mi days. But when we had limited time then I used to push it to 500 mi sometime further. I once did from just east of Dallas to North Florida in 30 hours or so. I only did that once tho.
Yes it can be a lot more stressful hauling a trailer. When your rig is 40 or 50 feet long then you can't maneuver like you can when you aren't towing. The least stress is to plant yourself in the right hand lane and set the speed control to 62 mph. Trailer tires are not rated for high speeds and you get a lot more blowouts if you try to travel at 75 mph.
BK