Your scenario hinges on a few quesionable assumptions:

Corbyn whips his MP's to vote against because he doesn't want to be held responsible for the outcome of the negotiations ("a bad deal for Britain") and wants a general election so that a Labour government can negotiate "a better deal".

At that point the vote can credibly be described as one between deal and no deal, and I have no doubt May will make that argument. Unless, of course, May turns the vote into a confidence motion. As your own scenario argues, Corbyn would likely end up with no deal rather than a better deal.

Then you have to assume that the DUP won't hold the balance in the Commons after new elections. What if Corbyn fails to win a majority, but May can have her majority again with he help of DUP or, worse, UKIP?

Then you propose that the same EU council that won't be sympathetic to Corbyn the old-fashioned socialist is going to go along with an agenda for reform that it has been resisting for many years.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman