It maybe possible to bring your own but I'm quite sure no one at FW will be able to help you. They will most likely give you the phone number of the outside company that provides internet for them and its really up to them on whether its OK.
It they do allow it, they will ask you for the MAC address of the modem to put in their system, its on the unit. Once on the system it should send down the config info to make it work. I used to do in home Geek Squad like work and installing customer supplied cable modems was something I did.
But even if you do buy that exact model there maybe different versions of the that model and you may have to be running a certain level of firmware.
Of course the bigger issue is do you know they have free wi fi through out the campground? I'm sure others here can tell you how strong it is and other tips to get a good signal.