I would venture to guess that, based on previous elections, even if the big-L's hadn't been a factor, about a quarter of them would have voted for the ticket anyway, and the other 3/4 would have left the ballot blank, found another protest vote or stayed home. The big-L's typically get 1% of the vote or so regardless from their true believers.
Note that Johnson/Weld had their best performances in states that were not considered competitive. The ticket got most of their votes from people whose votes weren't really going to make a difference anyway.