Two part reply:
First on the RV:
There are two products that improve the performance of the Winegard Batwings.
If your antenna is a Sensar II or III then the WINGMAN add on (Which is a UHF director Array) will improve UHF reception and give you about 50% more range (This may or may not bring in more signals, will bring them in better).
The second product is the Sensar PRO modle, this replaces the wall plate in many RV's with the 12 volt outlet, switch, light and antenna connection, You loose the 12 volt outlet but gain much, much more in terms of additional gain (Boost) signal seeker and signal strength meter to aid in aiming.
DO read the manual, this thing does enough I do not want to type it all out.
IF you have a matrix switch (Box of many buttons) this is the only product I would suggest installing between the switch box and the antenna.
This is what I use by the way.. Where I am parked I went from no OTA to several stations (park offers cable I use a mix with some automatic rube goldburg switching going on but well.... I can do that, it is what I trained to do, and its kind of fun having an advanced multi-dvr system that does everything those advertised Only ________lets you do all this" systems do... AND MORE.
Usually 8it works well, Last Saturday not so much but I fixed it Sunday morning. (Had to update a piece of software).
I do not use Sat.... normally it is not a problem.
part 2: The cabin
Two things can improve your Television reception.... (well 3)
First is this: Height is MIGHT (up to a point, like 200 feet or so, also 200 feet is a legal limit without special permits).
Put up a tower and go higher.. I have stories about how much difference height can make.
Second, improve the antenna,, Channel master makes some that are truly BIG, I mean like 15 feet long yagas with a range of over 100 miles (I know, I used one at my parents house, often getting stations over 100 miles away)
Part 3 is really 2b,, Aiming,, Channel master also makes a nice rotor, so does Alliance, and a couple other companies,
Not cheap, but effective, and while you are at it replace the feedline.
What happened when the world went Digital:
Not all, but many VHF stations moved up,, For example in Detroit channel 2 (VHF low band, which was the one that was easiest to see 100 miles away I might add) now broadcasts on carrier channel 7,, so where did channel 7 go, as I recall channel 41
The TV still says 2-1 or 7-1, but the frequency it is listening to has moved up band (7 is VHF high band and 41 is of course UHF).
Second, they cut power, big time, some are running as low as 10% of what they used to run.
Still, I get studio quality from 50-70 miles out with my Batwing, wingman, and sensar pro.