We had the OEM tyres on our unit until this year. Similar situation to you, Disney twice (from OH - close to same distance), Rhode Island, Mackinac, Carolina's, multiple weekend trips of 1-5 hours from home. Tyres were now 6 years old, and for personal reasons the unit had sat still for the last couple years. Knowing that the camper is used during vacation times and short weekends, and that I usually have 5 kids & wife in the TV, I decided that regardless of what the tyres looked like I was replacing them.
IMHO it's not worth having a bad start to a vacation, a messed up weekend, or a catastrophic failure resulting in severe damage to the trailer and possibly even the TV if things really go sideways, not to mention that if it goes real ugly the family isn't necessarily dealing with just an inconvenience but possible injury. Just not worth the risk, even with TPMS.
So I now run with Goodyear ST Endurance (made in the USA). Peace of mind has a value!! In addition, they're rated for higher speed and higher weight rating. My previous ST's were 65mph C's, new ones are D's and rated for a bit higher speed than I ever plan on running!! Having that additional margin for weight and speed means that I'm not running at or near max capacity on either weight or speed, and I like that extra margin. On some of those long downhills from the mountains I'm often at 70mph!!
'12 ST29SS Reserve
'05 GMC Yukon XL 2500, 4.10, Quadrasteer
1 wife, 5 kids, 1 rescue lab-mix