“The former will end Conservatism forever.”
The answer is to pack the Senate and the House with conservatives who will make the President play ball. He only signs the stuff that comes to him. If he doesn’t they need to override him.
How many Congresscritters and how many Senators would that take? Remember, there would have to be enough willing to buck Romney and their Party. I do not believe there are enough running to do that.
As a start, it would require 60 Senators, not counting many of the Liberal/Moderate ones in there now. I would feel much better if I thought your plan had a chance of success.