We've got a ton of cap space next year, and nearly as much budget room (assuming another ~70M budget). They need a couple D locked up (extensions, trade, or FA), and to fill out the bottom six. Plenty of cap and cash to do that. There are ways to trim 10M if that's the "only thing they care about" that don't include spending $5M on a fourth line at best player and losing your top pairing D. I'm sure they'd love to get some nice assets back, and prune the contract, but I don't think the contract is going to be the dominant concern.
If the goal for trading Ollie is A) get nice assets, B) trim salary commitment next year there's no point in making any deal that doesn't accomplish both. If it only "saves money" three or four years from now, and doesn't include nice assets, there is zero urgency to finding a deal that does both.