Maybe you can pick up cargo along your route...

The longer the trailer, the easier it is. The wheelbase of the tractor is not really an issue.

How in the world could you back up a trailer with a tractor with that long of a wheelbase?

Driving a commercial semi and hauling up to 57' trailers can hardly be called a retirement. It entails getting full time commercial insurance, a contract with someone that will arrange for your loads, fuel tax agreements and a whole lot more. That is without factoring in that a load will probably need to go someplace other than your planned vacation spot. Also, nobody will agree to arrange loads for you when you tell them that you only want loads that go to point A from point B. Driving a commercial semi is a full time profession. Leave it to the pros.

They look nice inside. I saw the prices though, $55,000 to $150,000. I'm assuming that is the cab modifications on your existing tractor.