Once again sir, you're not "amplifying" the original signal coming from the cell tower. Your throughput will always be limited to that signal strength. The weakest link will always be your inhibitor when networking. If you're seeing 1,000kb of throughput from the cell signal outside, you can "boost" it all you want inside, believe your lying eyes that you're seeing more bars on your phone, but at the end of the day you'll never get more than that original 1,000kb of throughput. It would be a wonderful world if we could do that, and we'd all share our boosted cellular connections across the campground, but that doesn't exist yet.
What you can do is get Starlink (
https://www.starlink.com/rv, bridge it through your own router with a captive portal and WiFi6, and share that connection with your neighbors. That captive portal could be a pay-to-play connection, just like at a hotel, to offset your Starlink costs.