Hi, Leslie! Thank you so much for posting this series on renting travel trailers. I looked all over the web for stories of folks doing this, as it seemed like a good deal to me. One the face of it, anyway. But I wanted to point out to other readers that they really need to remember your situation in the Gulf Coast is unique and may not apply to other areas.
To start, one's ability to make money at it totally depends on what the RV park charges for space rent in comparison to the prevailing rents for short-term rentals. Here, the cheapest RV park owner wants $350 + electricity. Even at $199/week, that's harder to make money at.
Of course, other factors are at play. In your case, your workers are year-round residents in high-paying industries like Oil and Gas and Chemicals. . In a tourist market like mine, and even in colder non-tourist areas, there is a steep drop in the number of workers in the off-season. So the vacancy rate might be unacceptably high during non-peak times. (While my guests aren't tourists, they are are movie industry workers, tourist industry workers, and construction workers...all of whom work a lot less or leave the area in the colder months.) Those who stay year-round are usually low-paid tourist workers who, first and foremost, need a cheap place to live. If I am not providing that benefit, they will go get an apartment. And, to keep warm, they are going to run space heaters in the trailers, so the electric bill goes go over $100/mo./unit as the guests use space heaters to heat the relatively un-insulated trailers. That also kills my numbers.
A question for you: How do you handle air conditioning? While I might have $100/mo. in winter electric bills, I also have air conditioning requirements during the summer months, so it's probably $50 in summ. (Fortunately, our nights are cool while yours are stifling, but still.) How do you keep your electric bills at $20/mo. average if the guests are blasting the A/C? If it is included in their rent, I seem them going off to work and leaving the A/C 24/7.