Consumer spending strong, travel at record highs, price of gas low, etc.  

You can also write off travel to and from the property and more.

It is like a tiny home on a trailer.

One question I'd ask is if anyone has done trailer parking?

There are definitely pros and cons to all situations, you would just need decide what is best for you.Would listing it as a mid-term (traveling nurses, doctors, business professionals, contractors, etc) or a short term rental be an option? 

I've been in Lisbon for around 4 years - initially travelling between London and Lisbon before settling.  

I have lived in both places but if comparing price and travel time I don't know which one to decide on.

Sounds like a cool idea though...the only place I've seen them is outside the US on Travel channels and such.

Are they an executive, an employee on 6-month business travel, etc.?

I have had travel nurses, medical students, and military members stay for multiple months in some of my STRs.