There may have been some voters like this but my best guess is it was a very small number. Not voting or voting for Jill Stein or some other maybe write in person would be the bulk of what disgruntled Sanders voters did. Sanders campaigned for H during the campaign a little bit as well.
I suspect if you lined up a hundred Bernie-voters...less than five would have gone to Trump as an alternate situation. I do believe that fifty-percent of the Bernie crowd simply stayed home and refused to vote. In states like Michigan, it would have made a difference...had they shown up and voted for Hillary.