Never heard of Standby Sams but if it's anything like GS Roadside Assistance it's probably a bust. I do like the RV Parks button at the top of this page, which works very well. I must admit that it has never occurred to me to plan for failure. Guess that's why I've never had a failure, lol.
Actually, I do everything I can prior to a trip to make sure there are no problems. One thing that happens a lot to trailers is tire failure. On my 5th wheels I've put truck tires on and in seven years and many cross-country trips I've never had a tire failure. Just one example of how I plan ahead.