I seriously doubt if a fillibuster happens.
Both political parties, for different reasons, want this bill enacted into law.
This is the reason that they negotated in secret. They knew it would create a firestorm and did not want it publicized until the last second. They hope that it will be passed before serious opposition can be organized against it.
Time is not on our side on this one.
We can give hearburn to the senators and start working on the congresscritters. There are a lot of marginal democrats in blue collar union member districts that can be trageted. The rank and file oppose it. Some union leaders like the catholic church are salivating at new members. But the rank and file know vaseline when they see it.