I have a directional antenna, called a "patch" antenna, mounted onto the stalk on the coach roof where the batwing antenna would normally mount. Being mounted there allows me to control the direction of the antenna from inside the coach.
You could then connect to that antenna, via the proper cable, a router which has a connection for an external antenna. When I get to the park I raise the antenna via the inside crank, point it toward the office, or the park antenna if I can see it, then power up the router and log into the park's system. The router, acting as its own wifi hotspot, then transmits a signal throughout the coach. The beauty of this is that only ONE device, the router, is logging into the park's system. All of your personal devices (PC's, tablets, printers, laptops, internet radio, etc, etc) log into the ROUTER, not the park's wifi. The router uses a system called NAT to redirect traffic to and from the park. The park's wifi only "sees" one client: the router. This is really handy if the park gives you one code, to use on one device.
Want to get it better?
Get a router which has "Wifi as WAN" capabilities. What's that, you say?
Imagine you're in a park with no...or bad....or really expensive....WIFI and you want to use your MiFi, or your phone. These act as small wifi hotspots, right? Well, you can tell your router to not use its wired connection, leading to the antenna, but instead to wirelessly connect to YOUR hotspot (say, your phone), for internet access. And then, again, to use its NAT capabilities to allow all your other devices to connect.
So, whether you use the park's wifi, via the cable and your patch antenna, or you use your own hotspot, you only have one active connection from your router to the hotspot, but all your other devices can connect simultaneously to the router for internet access.
Been on the road for 3 years. Works great. I use the Cradlepoint MBR95. This has wifi-as-wan capabilities, but does NOT have a connection for an external antenna. I have a slightly different setup, which I won't go into, but it's functionally the same as I've described. So, if you're interested, find a router with an external antenna connector, and wifi-as-wan. Be careful to get a router-cable-antenna combination which is compatible.