They do make routers like this and it is the only way you can do what you are looking to accomplish. Getting your laptop to reliably work on two wireless networks at the same time is not trivial in a fixed environment, but in a mobile environment like your command center, it would need to be reconfigured almost every time you connected to a new campground WLAN.
This should work:
View attachment 252703
You would want to configure your personal network with an unusual private IP range of 10.255.255.0/24 or something like that so that it would be less likely to conflict with the IP addresses you would see at the various campgrounds. I can help you set this up via email or PM if you like.
--Sky