He also said my GC could complete the install and knock 20k off the total, which I would do, so the total seems to be 355k to get the home in place.

Currently scheduled to close on my first triplex next month and excited to connect with other RE professionals in the area to help me along. 

Think that adding overhead heaters in the area of hot tub will solve the problem in colder months.

Why will your rent be LESS per month after the tenants move out and you fix everything up?

Also, given it will take > 12 months to complete, I'd focus on IRR vs.

I rent to one couple or small family for the full rental period - no less than 2 months and no more than 3 months.

When you sign almost all mortgage closing packages, you are signing an Occupancy Clause that states you are intending to live in the home for 12 months.  

I recently purchased a 2 unit property as owner occupied with one unit already rented out. 3 months after closing, I was laid off due to a restructure at my company, so I decided to rent out the other unit my girlfriend and I planned to live in.

My guess is that you will pay less per month with multifamily than a single family. 7.

The 2-3% points in extra cost are worth it if you plan on using as I described above because the use would be for a few  months at most and due to that short term use you can survive a rate adjustment up.But, if you have no plan to payoff the debt like when using for a down payment on a long term hold why pay the extra cost for flexibility and have the additional risk of the adjustable rate with the amortization looming when you can get a fixed rate second mortgage.