I don't compete anymore as the Marine Corps no longer provides free ammo, and I am not what I would call a "Master" but I do shoot very well. Teach even better.
To answer your last Q first, of course the wind can blow you OR the bullet that far off. Further too!
On the matter of changes to your standing pos. Consider the following, you have a 25 mph wind gusting from 10 to 4. If you are shooting texbook this places your feet at a possition relevant to the wind similar to the following two symbols. I\ Ibeing the alignment of your feet \being wind direction. Try shifting your weak side foot back just 5 or 6 inches more. This will bring you closer to bracing directly against the wind. Unfortunately, there ain't no such thing as a free lunch, and this also blows your natural point of aim all to Hell! The position places a bit more strain on your back muscles so you lose a bit of skeletal support, but with a bit of practice, you can use the modified position to your advantage. BTW You mentioned the term 8 rounder, so I think it's safe to assume you're shooting an M1. At 200 yards, the 10 to 4 wind you describe will push your bullet to the right anywhere from 4 to 8 inches depending on your load and bullet. This is not counting the sway of your body in the wind!
For sitting pos, unfortunately, the only advise I can offer is this. GET LOWER!!!
I may be preaching to the choir here, but try sitting on the living room floor instead of the Lazyboy. You know the pos, right over left. I remember in USMC bootcamp, we were forced to sit like this whenever we sat! We were all VERY used to the pos by the time we got to "Range week" and VERY flexible. After several weeks, several of us could sit cross legged and place our elbows on the deck! That's the best fix I can think of for sitting in high wind. Of course, the ROs probably wouldn't let you actually place your elbows on the deck, but if you can get close, that's good enough!
For prone pos, you're as low as you're gonna get.
Remember, you said you called all your "out" shots? If you called them, then you knew that your sight alignment/sight picture was off when you squeezed the shot off, so why did you sqeeze it off?
This was always a very annoying thing to hear when my coaches asked me this question, so I apologise, but it IS a valid Q. Some food for thought.
Your mind is your primary weapon.