This is a logical position for a UK Conservative and Unionist to take, and consistent with her position to date.
Uniform soft Brexit across the UK is the only way this can go and May and the Tories are gonna have to take whatever political hit that entails. It’s entirely navigable by any semi-competent PM, but May is proving to be even less politically astute in the job than Brown was.
I don’t think there’ll be a general election before spring 2019, though. The Tory leaders-in-waiting will let May grind through it all (and deny any opportunity of a Corbyn gov during the interim) before pouncing.