I have Apple TV and love it when I am home. It connects to my home WiFi network and is great for sharing anything to the big screen TV from my Mac or iPad. I've used it to watch movies, share photos or surf the internet.
When I am camping I have a Verizon Hotspot but am conflicted about how it calculates the data being used. I have read that all the data passing thru the hotspot is logged against your data plan even if it just between the Mac and the Apple TV, so this is what I did to allow me to mirror anything from my Mac, iPad to my big screen TV in the TT without the need for internet.
I have an Apple TV box ($99). I bought an Airport Express ($99). Using the Airport Express Utility I configured it to set up another network. There is an option to use the Airport Express without internet connection, which I did. This then creates a WiFi signal. You can choose the name for network during set-up.
Now, when I am home, using settings on my Apple TV, I set it up to use my home network. When I am camping I set the Apple TV to use my Airport Express Network. I also have to set my Mac or iPad to use the same Wifi network. Now, no worry about using any data because I am not connected to the internet. I can be in the middle of the desert with not WiFi or cellular data and still watch my Mac/iPad on my TT TV or connect it to a projector as a previous poster does.
I can carry my Apple TV and Airport Express anywhere and connect to any TV with HDMI and display on the TV what is on my computer. $200 but one large data bill from Verizon can be much more than that.
2016 Siverback 33IK
2015 Ford F-250 Lariat 6.7L V8 Diesel 4WD Super Cab
"If you don't know where you are going, any road will get you there."