Who is to say that handful of Blue Dogs (as you well note of which there are left -- a handful) vote to retain Boehner just to flip the bird to Pelosi and the Tea Party? Hoyer couldn't stop them and it's not like they rake in the DCCC bucks...
I don’t think that any Blue Dog (and you’re right, there are only like a handfull of real ones left) actually would vote for Boehner: in the past few decades, the only Representative to vote for the opposing party’s Speaker candidate was Jim Traficant voting for Hastert in 2001, and Traficant became the first Representative in decades not to be given membership in *any* committee. If a Blue Dog wanted to screw over both Pelosi and the Tea Party (which, along with Obama, are the three largest causes for their ranks dwindling so much), they would be more likely to abstain or not show up that day (which might result in Boehner’s reelection) rather than voting for Boehner, since they can claim plausible deniability for the former while the latter is tantamount to political suicide. (If they voted for Boehner, they pretty much have to switch to the GOP, and the only current Blue Dogs who might have a chance of winning a GOP primary in their respective districts are Mike McIntyre of NC-07 and Collin Peterson of MN-07 (and both would have to vote quite a bit more conservative to have a chance in 2014).