We are afraid that if hold on to the property that the market will eventually decrease and we will lose an opportunity to sell in this crazy market. 

We plan to fix it up, raise rents, decreases expenses, refi and buy more!

Hopefully these are accounted for or tested in the financials prior to the offer but it is rare for projected financials to show profitability decreasing over time as it is not what the investor wants to see.  

He also said that the floor joists are supported by a temporary support (see pictures).

By doing this you'd probably improve your cash flow, decrease your taxes and benefit even more from appreciation.  

There is significant risk that the US population will decrease.

@Ava Yuergens I don't think the returns are decreasing because of over saturation, I think it's because the cabin prices are going up rapidly.

Hello Short term rental owners,I am considering a property in the Poconos area with mandatory temporary membership fee for renters.

And even if there is a 5% decrease (or worse), that still wouldn't phase me, because price appreciation isn't a big factor in my strategy -- cash flow is.

Then it's a matter of projecting how much you can decrease expenses and increase revenue.