Awesome! I used Project Fi for 2 weeks with my 6P. As long as you have good T-Mobile coverage you will be happy with the service.
From my experience, I tried out Project Fi because as a tech geek I loved the idea of switching between carriers when one either doesn't have service or it's temporarily not working well like at a large venue. I think this was a ROM problem for me, as I never switched to Sprint, I was on T-Mobile 100% of the time, but honestly this is better since their network is miles ahead of Sprint. The second major reason for me switching was I was looking at ways to reduce my phone usage, and I thought that if I was charged per MB as I used it, I would use my phone less often when out and about. In reality though, when I was out instead of taking 30 seconds to check Snapchat I would spend a minute looking for and signing into free WiFi, waiting for it to connect and make sure it worked, then I checked Snapchat for 30 seconds. Also, I found myself spending a lot of time constantly checking data use on my phone and when background data was going on I was changing those app settings to block or minimize background data, and otherwise wasting more time. At the end of the day, I found that T-Mobile offered a better plan for the price with 5GB of LTE data for only $30/mo without any taxes, plus it includes unlimited music streaming and speed tests, which is the equivalent of around 750MB on Project Fi for the same price after taxes.
I still want to go back just because it's such a cool service and the support is amazing, but I think I'll wait until the prices come down a bit.
How much data do you currently use per month?
Though I don't know how long you had before your father fell ill while you were over there.