The property manager will be involved for years, and they want it to be something easy to manage.

If you want to scale, it likely won't involve you running your own renovations as a GC.

I assume there’s no realtor involved or they’d be upside down.

Ensure that the savings from the new loan outweigh the costs of the prepayment penalty and any closing costs involved in the refinance.6.

And treat this as 1/5th space as a rental.Or down the road, would it be better to have the entire property (home & garage/room) rented out to everyone involved and the property become an investment property. 

I won't ever close on another OOS property without walking it first but that involves paying for lots of flights and hotel/rental car costs if flying out there to make an offers but the $1500 to $3000 would be worth the cost to me to save on future headaches. 

Because first and foremost it requires you getting INVOLVED, putting in some rep's, and if you won't get involved and won't put in the rep's you will never, I repeat you will NEVER succeed in investment real estate or any business venture EVER, full-stop. 

We also see a lot of variance based on guest type, especially with travel nurses and insurance placements.

Short-term rentals (STRs) offer a way around these limitations by being considered active income if you meet certain material participation requirements, such as working more than 500 hours or 100 hours, surpassing anyone else involved.

Getting multiple contractors involved will be your best bet to get a reliable estimate, though you need to come up with a scope of work.