The celebration winning the Cup doesn't take away from the work that needs to be done for next season.
I truly believe all of Kadri, Burakovsky, Manson, and Kuemper are walking as UFAs. If I was a betting man:
Kadri to Philadelphia
Burakovsky to Ottawa
Manson to Anaheim
Kuemper to Edmonton
I think Nichushkin and Lehkonen are both re-signed to contracts that are more team friendly than we are thinking, and that Girard is traded in a package that brings back either John Gibson or a young-ish 2C.
There will be more work for next season, though. The 4th line will likely be 2/3 new since I don't expect either of Helm or Cogliano back (I think they both retire). However, the core is in tact:
Lehkonen - MacKinnon - Rantanen
Landeskog - XXXXX - Nichushkin
Newhook - Meyers - Compher
XXXXX - XXXXX - O'Connor
Toews - Makar
Byram - Johnson
XXXXX - XXXXX
XXXXX
Francouz
One of those open slots filled by Girard. I'm guessing one of Ranta/Foudy pushes for a 4th line role on the team. I expect JMFJ to be re-signed at league minimum if he's interested in still playing as a 7D.
Work to be done. The defending of the Cup starts today.
A lot will hinge on whether or not Sakic can secure a 2C and/or goalie in UFA.
If for example you can slot Copp or Trocheck at 2C without giving up anything off the roster then things will be looking pretty fine.
That said I suspect given how lax the organisation has generally been with the 2C and 3C positions beyond the Kadri trade that they might opt to give Newhook a shot at it and re-assess later, especially if it means that they can keep Girard. It's not ideal but might be workable with Nichuskin and Landeakog as the wingers to insulate Newhook.
Lehkonen - MacKinnon - Rantanen
Landeskog - Newhook - Nichuskin
Compher also held his own at 2C for a few games in the WCF and SCF which may play into this too.
Then there's also Meyers to consider. He was one of the most sought after college free agents in years and probably got some assurances of a key role if he signed with Colorado. It's possible that the front office view him as a younger Andrew Copp as their play-styles as pretty similar (hard working but limited-in-skill two-way LW/C) and have him pencilled in for an opportunity to work his way up the lineup.
For the record I'm not a believer in Newhook as a center or 2C right now, and Meyers has a lot to prove as even an everyday NHL'er; but I'm just commenting on what the Avs front office may be thinking.
If you go with internal options at 2C you can keep Girard and continue to roll 3 elite transition D pairs, and probably also afford to re-sign Manson. Barring a raft of injuries the roster should still be a playoff team without adding a 2C, but if it becomes clear by the deadline that an external 2C solution is needed then you'd still have the option of trading Girard for a 2C. By that time Girard will be healthy and (hopefully) playing well again which would make it easier to make a good-value trade for a 2C. Waiting 6 months may also yield more options as new 2C alternatives may come on the market that aren't available right now.
Again, I'm not saying that this is what the Avs necessarily should do, but I wouldn't be particularly surprised if they go this route.