John, although a little expensive I have used this hi-gain repeater (see
LINK) for the past 2.5 years and it works fantastic.
Now that 4G LTE is more available nation wide I don't use it very much anymore (use the built in hotspot on my iPad now) when on the road, but when I was using it all the time it certainly did the job well! I mostly used it during the summer at the Academy of Model Aeronautics (AMA) national flying site in Muncie, IN. They have Wireless around their 1200 acres of flying sites, but it wasn't always the most reliable at the campground. The most reliable wireless was coming from the omni-directional antenna on the roof of their Headquarters building about 3/4 of a mile away across open field. This Hawkins Tech unit could latch on to this signal from the HQ building easily! I just would mount the unit on the ladder of the Camper and point towards the HQ building.
Now, I mostly use it like you are suggesting, I have mounted it on the Barn where the camper is parked and point towards the house a few hundred feet away. I have perfect internet from my wireless router in the center of our house to the barn. This may be a little overkill for you application, but if you stay in camp grounds that have wireless "only" at the clubhouse or you are parked in a site that wireless is "iffy" putting this unit even on a desk pointed towards the source will help bring in those week signals to a usable level.
This repeater/extender uses a PoE injector to power the unit so the only connection to the unit on the camper ladder was a normal Ethernet cable, the injector was plugged in to 110v inside the camper. I had a ToyHauler at the time I was using it a lot, so I just ran the Ethernet cable out the ramp door and then closed the ramp door on the cable. It may be a little trickier in a normal coach to get the cable outside if that is what you wanted to do. I looked a long time for a outside weatherproof Ethernet jack I could install so I didn't have to run cable out the ramp door but never did found one...
anyway...sort of a long post to say this Hawkings Tech outside repeater/extender worked great for me!