A lot more common than you think... Many folks use the WI-Fi Ranger.. In a manner of speaking I do as well
The Wi-Fi Ranger (Full system) Consists of two modules and some cat-5 cable
Outdoor module (I use a Umbiquitti Nano Station Loco M-2, which as I understand is identical to at least one of the Wi-Fi Ranger outdoor modules) is what I call a Wi-Fi "Modem" it connects to the park router and outputs via Cat-5 Just like a cable modem.
The indoor module is a router.. slightly modified to power the outdoor module via the Cat-5 cable.. In my case I use a standard house router and a "power inserter" module that came with the NanoStation. The Router thinks the Nano-Station is a modem as well.
Before that I used a Linksys WGA as the "Modem" IT worked well. the nano better.
Finally 2 Rouku's plus other stuff.. You are going to overload the poor park's router.. You are what's wrong with Park Wi-Fi.