I've tried exactly what you're talking about, and, in my experience, it doesn't work. I'm fairly certain that the engine will still down-convert them to 640x272, then back up to your native res. Try converting one of the high-quality movies to 640x272 and compare how it looks and plays in-game to the same movie up-converted to your native res. In my case, the down-scaled movie looked better and played more smoothly than the up-scaled one, even though the latter had been up-converted to my native res. It also looked and sounded better than the movies that shipped with the game.
Even the hex-monkeys over at the Widescreen Gaming Forum never figured out how to get the engine to properly scale the high-quality movies, so we're pretty much stuck with 640x272. I've never had the opportunity to personally test the high-quality movies on a monitor with a vertical resolution of 1200 or higher, so I don't know if they'll work properly in that case or not.
If you come to the same conclusion I did, just convert them all to 640x272 and replace the originals with them. You'll still end up with better movies in the end.
EDIT: You've figured out how to batch-convert with RVT? Would you mind telling me how?
"They should rename the team to the Washington Government Sucks. Put Obama on the helmet. Line the entire walls of the stadium with the actual text of the ACA.
Fix their home team score on the board to the debt clock, they can win every game 17,000,000,000,000 to 24. Losing team gets taxed by the IRS 100%, then droned."