Reasonable except NYI needs a top 4 RHD after losing Hamonic, ideally someone that can take top pair minutes, and you're taking their only RHD prospect.

They can afford a 1st, they can afford De Haan because of Sebastian Aho if need be. This trade needs another leg

What would you suggest? I would be willing to send along Siemens or a higher draft pick, or instead of Pulock possibly take Dal Colle...thoughts?

Any LHD is fine, but NYI would really be more interested in Barrie than Duchene. Could make a bigger package and trade Duchene + Barrie to get NYI to gut their future, but that would blow up any hope for COL in the present.

COL's problem is the teams that might want Duchene (those with a real chance to win the cup in the last 2 years of Duchene's contract), are not the teams with the depth to give COL what they want in defense.
Basically there are no cup contenders that NEED a 1C/2C, it would just be a nice bonus they would pay a top 6 prospect + bottom 6 roster player + late 1st draft pick.

There are plenty of 30+ players that are good and cheap to fill out a roster today, but you have to make room for them. I'd suggest COL trade away everyone but MacKinnon + younger to take as many chances of acquiring players around his age so they can grow together. You can't fix all of COL's problems at once, that option isn't available and delay is no solution.

There's a good future top 6 between the ages of 20-25.
Landeskog 24 - MacKinnon 21 - Rantanen 20
Nieto 24 - Compher 22 - Jost 19
+ Yakupov 23

Trade for prospects <25, at least half of returns spent on D:
Soderberg 31, Comeau 31, Wilson 27, Colborne 27, Duchene 26, Adringhetto 24

can't trade Johnson, Barrie is 25 which is young for D but would trade to NYI for Dal Colle + Pulock + 1st + 2nd
I don't see the point of giving Barberio any ice time

Note: COL has 1 RHD signed other than Johnson or Barrie. 19 yo Nicholas Meloche from 40th overall in 2015 draft. They have 6 LHD after Zadorov and Barberio.
only 11 D signed.
3 are already on the team in Johnson, Barrie, Zadorov
4 are going nowhere: Barberio, Lindholm, Boikov, Geertsen
4 have some chance at the NHL: Mironov 22, Bigras 22, Warsofsky 27, Siemens 23. I'd bet on 1/4, 2/4 would be optimistic.
4 NHL D under contract, maybe 5, is the problem. It's a joke. Between the draft and signing undrafted players, a good team would average developing 1 NHL D per year. Not only is COL undermanned, they are on track to have even less NHL D in the future as they're retiring/departing faster than they are being brought in.

There is no excuse for there not being 16 signed given it's the biggest problem with the Avalanche. You can't speed up time so you have to roll the dice as many times per season as possible.

De Haan, Dal Colle and a 1st would be fine IMO. Isles could try and replace him with Cody Franson