Colorado and Philly seem out if the question due to expansion draft. Toronto and Vegas have to make absurd trades for it to happen so I find those options doubtful. You can probably count out all the tanking teams as well as any team set on RD like Boston, Montreal, and Carolina you can also count out any team implementing an internal cap.
My gut says he resigns with the Blues but that's a boring answer. So my top 3 will be the remaining teams who can afford him, have a need for him and can protect him in expansion
1. Winnipeg - Obviously need defense and an eventual top 4 of JoMo, Piet, Pionk, and Heinola sounds sick. They have the cap and the room expansion slot.
2. Vancouver - With rumors of Marky walking they could spend their cap space on just Piet and Toffoli instead of Tanev. Still probably 1 contract needs to be moved out but thece been reported to be pretty active already. Edler is a UFA next year so outside of Myers i have no idea who they would protect on defense.
3. Calgary - Flames have 5 UFA defense this summer, 3 RD. However they have some prospects pushing for roster spots so they only really need to fill 1 top 4RD spot. They have the cap space to go after 1 big/bigger name this summer and with Valimaki now being expansion exempt, as well as Gio likely being exposed there is a lot of logic to persue a top end defender.