I agree, a no deal Brexit would be disastrous for the economy and I know a number of MPs want to rule that out for that reason given the economy has been growing the past few years.
As for the idea of a second referendum (something that the Lib Dem leader Vince Cable supports), Theresa May has said time and again that it would be a defiance of the wishes of the voters. Though we know more than we did back then, so if it did happen, I'd also think it'd go along the lines of "are you sure you want to go through with this, knowing what you know now?".
Only 78 labor MPs supported a second ref today. The numbers aren't there. And again, the same question I posed to Striker stands