The only thing we know know is that the Republican Senate Caucus will be discussing the pending vote at 2:00 PM on Tuesday. So all we know is that a vote will (if not delayed again) come after that meeting.
Also so worth keeping in mind that Republicans are currently at only 51 Senators with the continued absense of John McCain. John Cornyn said Monday that he offered to rent an RV to drive McCain to D.C. for the vote. That, obviously, never materialized.
Reportedly, Murkowski's office was telling constituents on Monday Morning/Afternoon that she intends to vote no on the motion to proceed.