And a bicycle to ride home upon....

A trailer with identical tires to the bike could make a logistical difference.

A crafty builder could make a two wheeler that could be converted with a bungee cord stabilized one wheeler if you lost a tire catastrophically.

I can see how to start building it in my head. Few welds or threads and the rest pinned with something like this.

Sailrite - Fabric, Canvas, and Sewing Machines Since 1969

 

I like the common size single wheel idea, and with so many cheap bikes around it would be simple enough to rig a front and rear bike wheel on the trailer. The mono-wheel trailer would be super handy if it could be towed at a narrow, folded width when empty. Hmmm, maybe even flipped up on its side with a wheel mounted between what had been the cargo deck and a raised railing. The design possibilities are endless.

 

Whatever you do, don't make the stupid mistake I did and buy a fordable bike with less than 26" tires. I ride an Elby Electric Bike which I love and unfortunately is not cheap ($3500-4000 with accessories) and I also bought for emergencies a beautiful fordable bike but with tires less than 26". It hurt like hell peddling and did not go very far because of the size of the tires. I wound up selling it at a substantial loss.

 

Extrawheel is small one wheel bike trailer. Pretty slick.



this shows how it works

 

The advantage to my cart is the ability to reconfigure the frame for longer taller and loads, single wheels can not perform .
If you have a friend that has a broken leg how do you get them to help ? seriously .