You can lock in a rate that's lower than inflation, it's basically free money. 

Sure you did, and I doubt the contract allows for an increase due to inflation (unless he had that clause in there).

We have 50k for a down payment but not sure if purchasing a second home in the Portland/Vancouver market is smart due to how inflated the homes are.

I also didn't know what inflation was.

You'll find that the cheap money (low interest rates) today will pay off in just a few years when you wealth in invested in real estate that grows about 8% annually, about double inflation. 

If your all set and your total loan falls under the SFR limit I would still suggest looking at conventional lending just for the immediate issues on the rise with inflation. 

There will continue be a strong demand for real estate because so much money printed recently and people know that real estate is a good hedge against inflation. 

Inflation - I am not a macroeconomic expert, but this one seems clear at this point.

In the first half of the year prices have increased more than 11%, well above the broader inflation rate.

Assuming 5% inflation, it will cost $2552 in 5 years.