Hi, If I understand your situation correctly and if you live in a newer house, I would suggest looking into powerline-ethernet adapters that would enable you to extend your wired LAN from the 2nf FL FIOS Router location to the office in the basement. Something like this: https://www.amazon.com/ACTIONTEC-Powerline-Ethernet-Adapter-PWR514K01/dp/B00CB2F65O/
I assume that you have an ethernet home-run from FIOS terminal in the basement to your FIOS router upstairs. Obviously, you can move the router into the basement, but then your WIFI network would probably suffer and if you may have devices upstairs that might be using wired connection to LAN.
I hope my suggestion helps. I personally used Actiontec and had very good results.