Boston has what amounts to zero cap space, although I guess they could LTIR Hampus Lindholm until the end of the regular season ... but he supposedly week to week, so maybe not. Vancouver could retain half of what they're paying and Boston would "only" have to shed $2 mil and change but with their roster I'm not sure how that works. And Vancouver definitely has zero cap space so whatever they bring in, they've got to ship out.
And before anybody asks, no ... Zucker would make no sense for the Canes. He's a 3rd liner at best. A solid, versatile 3rd liner but that's all.