I suspect an alternate proposal, such as Wyden-Bennett or BaucusCare, would be passed with some modifications.
BaucusCare/Wyden-Bennett are both from 2008 and are too the left of the final Obamacare. At the time Obama was supporting a public option without an individual mandate, which Clinton attacked because it didn't give everyone coverage. CLinton supported an individual mandate without a public option. By the time 2010 rolled around, ACA had moved to the right of Clinton in the hopes of trying to appease various dissenting Dems to cobble together enough votes to pass giving up on the public option, but keeping the individual mandate.
BaucusCare/Wyden-Bennett were also more disruptive because they sought to move away from employer based care.
Neither would have passed the Senate. Robert Bennett himself was perfectly willing to go along with voting against any healthcare plan, because he was an establishment/business wing GOP shill and that is what they wanted. So yes, he would have voted against his own bill from 2008, in late 2009/early 2010 and once Scott Brown was sworn in, any healthcare plan was dead.
All they could do was pass what the Senate had passed in December, in the House and use budget reconciliation to touch it up afterwards.
There would have been no going back to the drawing board, there would have been no healthcare bill passing. And the impact on 2010 would have been either nothing or would have made it substantially worse. 2010 was decided because Wall Street got a bailout and Main Street didn't, and the economy was still horrendous for most everyone, healthcare was at most a side note politically and a distraction and waste of political capital for the Democrats in terms of the issues that ultimately decided 2010.