From my experience at camp grounds without much cell service, 3g is usually barely any connection and usually doesn’t work for anything except the basics and might mean you actually don’t have service. I’d say go the directional antenna as you will likely spend a lot less and not have to deal with expensive range extenders for Ethernet. I personally would build the antenna to save costs but it might not work as well.
Then I would look into this and get a cell hotspot or just use your phone
https://www.ciena.com/insights/articles/How-I-built-my-own-mobile-cell-tower-prx.html
From my experience at camp grounds without much cell service, 3g is usually barely any connection and usually doesn’t work for anything except the basics and might mean you actually don’t have service. I’d say go the directional antenna as you will likely spend a lot less and not have to deal with expensive range extenders for Ethernet. I personally would build the antenna to save costs but it might not work as well.