We don't need to trade Willy.
Kessel's retention also comes off the books when it's time to re-sign Mo (if we do). So we're already working with 6.2M off the bat. We can trade Kerfoot and re-sign him no problem.
We could make it work, but it would this and last seasons spendthrift depth look like a lotto winner splurge spending. Assuming 7.5 to Mo, 4 to Hyman, and an 82.5m cap we'd be sitting with 17 million in space for all of- a complete bottom 6 F group, both goalies, Sandin, a 6 D, and spares.
It's doable, but you have to wonder if at some point (hopefully with a cup) we step off this tightrope and extend the window by recouping some major young assets.