We could probably manage the payments without selling the cabin; however, it would provide significant cushion and allow us to pursue some other opportunities. 

I think with 8 units you have more income cushion if you have a vacancy or an expense like an HVAC issue.

More CF (per door) adds a cushion because things will happen (unexpected costs).

We're not looking for an immediate huge ROI, but would like enough to cover costs and pay for our flights a few times per year(plus a cushion for repairs, upkeep, etc), while we ultimately wait the 10 years for Tulum to go through its growing pains, and then have a much more valuable property on our hands.Even with this conservative plan, we would still need to locate the right property in the right location that appeals to us and renters NOW and is poised to become more desirable as Tulum blossoms.

Though high rates, we keep 100% of the interest paid, we used it as a cushion to buy our current home in order to rent out the first home. 

As far as reserves, I've got a pretty good cash cushion built up, plus a line of credit in case of a dire emergency.While I haven't exactly budgeted for CapEx, my initial plan was to set all of the cash flow aside in a separate checking account to build up toward replacing the roof, separating the electric and hot water, etc.

(But perhaps not in as cotton-cushioned locations).Remember, your TENANTS are still paying off your investment mortgages for you, whether your own other income soars or nor not.

It's the 2008 Crash that kept me from making double the money with the long term Buy and Hold, but, I had a cushion when I bought the properties at a discount.

But you must stick to your numbers. hard money is expensive and if the job goes sideways you need as much cushion as you can get to cover the carrying costs.

The fact that I could save so much and continue to grow my cushion was a big help.