Alex Pietrangelo isn't signing in Colorado, nor do I believe Joe Sakic will pursue him. The defence is going to be built around Makar/Byram/Girard and the vets are EJ/Cole. You fill in the others with spare parts unfortunately because it's impossible to build an unreal defence from 1-6 unless you draft every single one of your guys.
Priority #1 this offseason, though, should be finding a Ryan Graves replacement. Not so much that I want him off the team (though if he asks for anything more than 2.5M I'd let him walk), but he can't be in your top-4. If he is, you'd better have A+ goaltending.
Unless the Avs want to go out and sign Robin Lehner to a long term deal, which I'm not opposed to in the least.