We replace our tires for our RV every five years and been doing so for nearly a couple of decades. Yeah, none were worn out looking, or overly dry and cracked, just done it for peace of mind. Happy to report never a blowout in all those years, not even a flat tire either.
With TPMS you plan to install you could keep a watchful eye on them as you just plan to RV within your state, maybe get another year out of them. Air them up properly and keep your speed down, it's possible to squeeze more life out of them. Me, I would replace them and enjoy.