That wouldn't work as well as the options described in the thread Watford linked to. The problem with your option is that many Leave votes would choose either 'Leave May's deal' or 'Leave no deal' as their first choice, but their second choice would be to remain. Your method would leave us where we are now, with most people saying that we want to leave, but when the method of leave is revealed the majority wishing we would remain instead.Yes, I find it puzzling that so many are still saying it would be difficult / would split the vote / etc.
You have a referendum that has two questions:
1 - do you want to leave / stay?
2 - if the outcome of the referendum on Q1 is to leave, then which option would you prefer: Mays deal / no deal / whatever else is on offer at that point?
This way, whichever way you vote, you can then have a say on what sort of leave deal you want if the vote is to leave.