No chance the leafs give up their best left D propect plus Gardiner. I think the deal centres around Gardiner, likely a protected first(top 1-10), and b level prospect.
Whoever gets Trouba will likely be looking at 6 million plus which if I am the leaf fan/management I really question because Reilly who is much more accomplished is being paid far less. Unless that is two years of UFA status included it doesn't send a good message.
If Leafs management determines that Dermott or Neilsen can step into the NHL next year and be 2nd pairing defensemen then I am completely ok with giving up Gardiner.