Read the entire article and it made a lot of sense to me. We still have over a year till the election and people have short memories. And as Silver pointed out, there are very few competitive races in the House. Which that combined with the strong historical trend of the President's party losing seats (or at most winning a small handful) makes it very unlikely the Democrats will regain control of the House.
Personally, I think this so called shutdown is one of the most overhyped political stories in recent history. The vast majority of the federal government is still up and running and hardly anyone's lives have been dramatically impacted by the areas that have been "shutdown". Reminds me of the scary "draconian" sequester budget cuts were all told to fear which seem to have been implemented without causing an economic apocalypse. Frankly, I hope the shutdown drags on and on and people might realize, "Hey, we're getting along just fine without this extra spending. Maybe we should make some of these cuts permanent." But I'm probably hoping for too much there.