They (the GOP Congress) will just have to take longer than they wanted. As long as they get it done before the 2018 mid-terms, "late" will not be an election cycle problem.
Understand that it took the hapless Democrats a full year to pass their law, and they had zero opposition from the GOP. Besides, their bill failed on 5 occasions, with Harry Reid canceling the Senate vote five times because of lack of support. It only passed into law because of his use of the 51 vote "nuclear option" on the sixth try.
I doubt that the Speaker will call for a House vote if he believes the bill will fail . . . . but no matter, it is not the end of the world. Leadership will just have to regroup, rewrite the proposal as they live to fight another day.
While the delay, if any, mayl alter the GOP plans for a comprehensive tax revision this year, the GOP can, nevertheless, pass a tax cut for the middle class and Big Business. Understand that a middle class tax cut that is retroactive for 2017, will win the mid-terms in 2018 for the GOP. Obviously, if the tax cuts give voters a break come April 15, 2018, they will vote their pleasure in favor of the GOP in November.