I have met one person that I would consider to have experience with long term biking. She was in year 7 of her never ending bike tour that started in S Africa, up to Europe, east to Asia, down to Australia, back up to Asia and China, then to N America, I met her in a campground in Oregon on the Pacific Coast. That was in 2014, I have no idea where she is now.
She used muscle power and pedals, not e-bike, slept in a tent. She estimated that her bike had 100,000 km on it, but most of the parts had been replaced a few times. The bike frame had so many location stickers on it I could not find a brand name. Her front panniers had the full 7 years of use, Ortliebs. She was having some trouble with her 2 year old tent, we helped fix a bent pole.
If you want to go on a never ending bike trip, skip the trailer, skip the electric drive, and buy some quality gear that will hold up for long term use.
There are a couple of guys that have posted lots of videos on youtube, Bike Touring Pro is one and another hosts a site called cycling about. They (independently of each other) have been bike touring for years before Covid stopped their travels, they both have good quality gear and no e-bike.
This is a link to a free magazine on bike touring, you can download past issues. This is not the long term touring like you are talking about, but has lots of articles about people on bike tours, and it is free.
But if you are locked into an e-bike and mini-RV trailer, good luck with that.