The Leafs are undoubtedly going to be in a cap crunch
Nylander at 7
Tavares at 11
Matthews ~11
Marner ~9
They have about half their caphit on 4 forwards. Rielly is locked into a good deal at 5 million.
Unbelievable duos on their top 2 lines.
They have all their draft picks, aside from this years 6th, in the next 3 drafts to go along with an extra 4th and 3 extra 7ths. They can make some moves at the deadline this year to get the biggest D on the market.
They can't trade guys like Liljgren or Sandin, as they will need their ELC's on the team to counteract those contracts.
They are going to need to ship out Zaitsev/Gardiner for sure, I'd see if Gardiner could be had for a penny on the dollar. He'd fit in nicely on the 2nd pair.
They should go all in this deadline, even if that means something over the top like getting Karlsson from San Jose if San Jose is out of it. (They'd have to compensate San Jose for the "Hoffman Clause"). The cup is very hard to win, and they are not only hot this year, but they'll have the accrued cap space at the deadline to make a big rental addition.
Your estimates might be low depending on the term. I think they could get both Matthews and Marner at the numbers you have above, but they'd have to be on shorter term deals. If they want to go 8 years with each of them, they aren't getting Marner for less than 10. Matthews is going to hit it out of the park I think. If they get Matthews for anything less than McDavid's cap hit on 8 years, I'll be shocked. McDavid is better than Matthews, but McDavid had that story (whether manufactured or not) where he left around 1M on the table after agreeing to his contract. He also signed the year before the cap started making big leaps again.
What I think will happen is they'll get Matthews on 8 years at astronomical money, and then they'll have to make consolations with Marner where it's a 4 or 5 year deal instead of 8. That, or they sign both to 8 year deals, and trade Nylander to a budget team like Carolina after his massive bonus is paid, and they end up actually "winning" the Nylander situation by having retained him for 1 more year, and then having gotten a greater return for him in July than they would have now since they'd be picking up so much of his salary via his signing bonus.
I'd love to see Arizona go and mess their team up by signing Matthews to an offer sheet, but when Toronto already has Tavares, Nylander, and Marner, as good as Matthews is, that type of play might end up being a Herschal Walker type situation where those picks could end up being four consistent top 5-10 picks that provide Toronto with a bunch of top end ELC/RFA talent to insulate their core.
(Obviously, I am discussing the prospect of an offer sheet knowing how big of a long shot that kind of thing is....Talk about the Leafs trading for Karlsson and an Arizona Auston Matthews offer sheet in the same post....this will end well)