Thank you all for the helpful comments regarding TPMS.
We are gun-shy regarding tire blowouts because we had two of four tires blow out on a single trip. Being that we only carry one spare, it was a huge mess waiting for roadside assistance. We aren't sure why the tires blew. The tread looked good, the pressure was at 50 psi, and we had a lightly packed trailer (approx 4900 lbs). This was our first weekend trip with our newly purchased 2007 Forest River Rockwood TT. We drove about 75 miles and the left rear tire (tandem axle) blew. We changed the tire, continued the trip, and camped for the weekend. On our way home, around 100 miles into the trip home, the front left tire blew. We don't know when it blew, we were rolling along on 3 tires at 60 mph when thankfully someone honked at us and indicated a flat on the TT. By now we had no spare, it's Sunday afternoon when roadside assistance costs 3X the normal price, and service is few and far between. We waited 6 hours at the side of the road before we got someone out with a tire and a jack that could safely lift the trailer.
The tire experts inspected the tires and agreed the tread looked good. The only reason they could suggest for the blowouts was that the tires were 2006 tires. We since leaned that tires should be replaced every 5 years regardless of wear. We replaced all five tires (including the spare) with new tires, but we want to be able to know that are tires are safe and the mirrors on the tow vehicle don't show the TT tires. Hence the TPMS. I think the best we can do is check the pressure manually each morning before we start out, and hope the tpms works if ever there is another blowout.
Thank you!