Reviving this as Marek mentioned him potentially going to the Isles which could make sense. Lou/Allvin obviously made a big deal last season and Kuzmenko will have some familiarity with Horvat, .
Realistically Isles would need to send back a similar contract the other way. Pageau is really our only guy without an NTC that fits that bill but would leave us with a pretty large hole at 3C - although maybe they finally want to give Ishkhakov a shot. Roy seems comfortable double shifting guys for a majority of the game, so maybe that would just mean more minutes for Nelson.
Another scenario I could see is shipping out Lee with some slight retention. He's still serviceable enough and could see it being sold as bringing in a high character dude for cup runs, while allowing us to name Horvat the new captain. Lee might waive for a chance at a couple of cup runs and for all intents and purposes it feels like Horvat is already the captain.
Last scenario is something involving Nelson which would suck for us and would probably need to include Vancouver's 1st and a Raty-esque prospect to basically mirror last year's Horvat deal. Nelson is signed into next year and then will need a new contract at age 34 coming off of a few 35+ goal seasons. We need to sign both of our top pairing defensemen that year so it wouldn't surprise me if they decide to maximize the return on him.