Absolute insanity. That's, what, lose nothing, pick up GA, AZ, NV, NH, CO, OR, WA? Or maybe he's expecting to flip California instead? There's an open seat in Vermont, I guess.
As for the House, that would be the biggest loss/gain since 1948, or 1938 for a midterm. And although being so narrowly in the minority makes it easier to win back the majority, it actually makes huge swings unlikelier since there's less room for growth. After the blue wave of 2006/8 receded, it left a lot of Democrats high and dry in Republican-leaning districts to be flipped right back in 2010.