Surge protector performance is rated in joules which is the amount of energy they can absorb. Exceed this value and the MOV and associated circuitry internal to the unit is destroyed or rendered ineffective. Then any surge protection is nullified.
"I dont know about Progressives, but Southwire says theirs should last “indefinitely”....... Well, I suppose if they don't get hit by a surge value exceeding their ratings, then they would last indefinitely. In that case, one doesn't need surge protection. A direct strike by lightning and nothing survives, surge protectors, circuit breakers, and such. All will be destroyed.
Most lightning strikes are "near by strikes" and are not direct. The nearby strikes will induce an elevated voltage in power lines, CATV cables, and telephone circuits. This is where surge protection becomes most effective.
So you do have a surge protector or some such device on the site at the power pole, but what about the CATV cable between the power pole and your RV? Oops, bet you forgot about that one. That is a path into your RV.
We lived in S. FL for 15 years. That area is known as "the lightning capital of the world". During those 15 years, both in our boat on the ocean, and our home with my 50 ft ham radio tower, plus having an EE degree, I attained a great amount of knowledge regarding lightning and power line surges.
Be assured I confess that I am NO expert on the subject. I do have several papers that have been published on the topic of lightning and surge protection.
Take all precautions regarding the proper use and placement of surge protection devices. Perhaps you'll get lucky and experience no damage.
Bob