In Alaska you will see a lot of large antenna that look like they are pointed at the ground several hundred yards away. I suspect my antenna is half again the size of sue t's. There are two issues, North and West. The more you increase either one the less the signal. My suspicion is that the typical RV upper end antenna quits functioning somewhere between Ft Nelson and Whitehorse. I will know more this summer when my brother comes up.
Some RV parks have cable, some don't. Charley Lake and Toad River have it. Teslin does not.
On the Kenai in some places you can get over the air, and some parks have cable. Closer to Anchorage or Fairbanks both should be available.
Mind sue. t.'s comments on WiFi. Some are only in the office or restaurant, some are broadcast. In Alaska you usually have good enough cell service to use the mobile hotspot on your phone if you are in a commercial campground or near city.