I have been using a SlingBox for the last 5 years in our TT. There are a few things you need to do if you want to use the SlingBox alone. 1. You need to pick a site as near to the CG's access point (AP) as possible, 2. You need to put the laptop as close to a window (facing the AP) as possible. The Wi-Fi signals operate on a line of site and trees... other TT's... will affect the signal strength/quality. The quality of the picture will automatically be adjusted by SlingBox to match your Wi-Fi signal strength.
The above is just using a SlingBox without the aid of a Wi-Fi Signal Extender. The Wi-Fi extender will amplify the signals to and from your TT. We have picked up the Wi-Fi signals from a HomeDepot that was 1.5 miles away on a ridge (Colorado Mtns), and we were able to watch the SlingBox.
For more information regarding the Wi-Fi Signal Extenders check the Wi-Fi Signal Extenders
social group. I do not recommend using the SlingBox without a signal extender.
For around $100 you can get a Wi-Fi signal extender. For about $15 you can purchase a 2nd hand Wi-Fi router. You plug the Wi-Fi Signal Extender into the Wi-Fi router and you can access it with your tablets, smart phones, PC's, slingbox...
A regular movie is about 4 - 5Gig in size... if you do not have unlimited data on you phone and you use that for your data it could cost you some big bucks. We are currently in the Blue Ridge mountains and yesterday, I watched the Tampa Bay Ray's season opener yesterday afternoon (TB lost).