Miyazaki himself doesn't care if The Wind Rises doesn't do that well in America; he's repeatedly stated that his films were written for and aimed at Japanese audiences specifically and if they happen to make the transpacific leap successfully, then it was good fortune.
To be honest, I thought it was very very cheap of Disney (or more accurately John Lasetter) to suddenly jump on Miyazaki's final film just to try and win an Oscar (Lasetter has nothing to do with Frozen, which of course will sweep the board). If they'd been sensible, then they would have realised a film about the man who designed the planes to bomb Pearl Harbour wouldn't appeal to American audiences. Nostalgia's the current trend, so of course people would be more engrossed in the LEGO movie, which is associated with happy childhoods, than a foriegner designing war planes, which is associated with the tragedy of World War II.
By the way, I know what the Wind Rises is about so please don't mistake my words for my thinking Miyazaki was glorifying Japanese Imperialism; he certainly wasn't.
All that said, I'll be definitely seeing it when Studio Canal finally get here in the UK in May (which shows much Disney give two figs if Buena Vista can't even be bothered to distribute it internationally). It's been a long time since Ghibli have produced something that isn't slice-of-life/light-fantasy...
Just my two cents.