The only scenario I can envision where Domi gets traded is a straight hockey trade, likely one-for-one, where a youngish D man (21-25) who is either currently playing top 4 mins or could play top 4 mins next year is coming back. That D man would likely be a LD with team control.
But, I think the most likely scenario is Domi is not traded and signs this summer. I don't see a contract problem coming and if there is, Habs can take him to arb and try again next year when there are lots of roster questions to be answered. His QO is something like $3.5M so he will definitely be qualified.
Personally, I see a 5-6 yr deal for $5.5-6.5M AAV coming this summer. There is some idea that the Habs don't really need Domi as they have a bunch of young centres coming but Domi should be able to transition back to wing without much issue. He's been a winger most of his career and brings a lot of speed, skill, and grit to the team. I don't really see a fit with Tampa and if the basis of this deal is the idea that Domi will be asking for too much $, the Habs are in a much better position to deal with that than Tampa.