Alienate the 52 and the 48 and win the next election? Something tells me you arent going to be snapped up as a political strategist any time soon.
I know life long Tory remainers and Brexiteers both saying they will never vote for them again. Labour are best off sticking to their plan, it isn't their deal and isn't their responsibility to push it through parliament when it doesn't meet their 'tests'