Did some digging on Wikipedia to see the last time that a British government got slaughtered on a key motion by a large margin and you have to go back to 1924 when Labour under Ramsay Mac Donald lost a no confidence motion by a vote of 198-364

May’s 202-432 eclipses Mac Donald’s margin to become the worst loss by a British government.

I e-mailed friends in the UK asking what they think the outcome of a snap election would be and their consensus is that there would probably be a minority Labour government with Corbin as PM. with Scotch Nationals and Liberal Democrats tacitly holding the whip hand.