I think a lot of RINOS want to lose the midterms.
You can always point to people who are on their way out of the Republican Party. Christie Todd Whitman is going to follow Steve Schmidt, Colin Powell and the Eisenhowers out the door. Bill Kristol is going to hold the door for as many party-poopers as he can, while not actually going through it himself.
But I doubt Republicans in Congress want to lose. What a lot of them want is to get back to the private sector and make money. Chairmanships are term-limited, and Congressmen who've been chairs for years don't want to go back to being rank and file members, so they are opting out. Democrats are offering more moderate candidates in Republican seats that they think they can win, and some of them will win.
It would be a surprise if any Republicans in Congress are looking forward to turning power over to the Democrats with all the investigations and impeachment proceedings that a transfer of power would involve.