Given the duration of the hold I'm thinking of, then I don't think a HELOC would make sense. 

I had a 5.6m deal that needed to be extended.

The deposit is for damage beyond expected wear and tear as well as any shortage of rent payment (if your lease is written properly).It does not cover carpets/floor wearing out, paint needed due to being occupied for an extended duration, any plumbing issues, not the result of negligence, such as slab leaks, cracked sewer lines, etc. 

Even if the rate is higher, by refinancing you will extend out the 30 year term by starting a brand new 30 year loan thus giving you more cash flow.

The property has 2 existing tenants that recently extended their leases in July.

I just extended my HELOC one more yr at 2.5%, and yes, its a variable rate that can go up to 20%..

If you don’t like to gamble buy the 5 year extended warranty for $100 ($20 year is another $2/mo, now you need to charge $4/mo extra to provide washer/dryer.)I’ve had more problems with refrigerators than laundry but I certainly wouldn’t try to rent out a home with out a fridge.

I am thinking that Garrett is talking Amortization terms as opposed to loan duration.  5 Year initial fixed with 5 year renewal with some kind of cap and 30 year amortizations seem to be the most common products out there at least for Multifamily, not sure on storage.

@Richard Sherman update: I got the seller with owner financing to extend same terms for another 13 years!

Currently I am getting ready to build a nice Sliding RV gate, and I have just recentlyfinished building a nice block wall around the property as the old one was falling down.So I am thinking my best bet is to do all those things, get in some good tile, re dothe kitchen, extend the back porch, close it off add 2 bedrooms and another bathroom.