Anything over $1m is just wasted cap space.
Personally, I think Monahan would be a bad move. His body is completely broken. If it somehow held up through the deadline, I can't see it holding up through the season and playoffs. Add to that, he plays with an incredibly slow pace now. Unless the Avs want to change their style.. he's nothing more than a guy you try to get 7-9 minutes out of 5v5 and a 2nd unit PP guy here.
To me, get two good defensive players with skating and/or size for the bottom six. Preferably one that is a true center. Kampf or Haula (not both considering the contracts they are likely to get) would be one of my top targets. Haula isn't a true center, but he's a swiss army knife style guy who can play there. Kampf would be my top target. Good defensive center who isn't a complete black hole offensively. If you get Kampf... go out and get a buzzsaw... Miles Wood would be ideal there. Then via trade... get a promising 2C on a good deal. PLD would be a very solid choice with some 1 year risk to him. Wouldn't mind that move at all though. Mittelstadt adds risk, but showed a lot of promise last season. Even for argument sake (and this isn't proper value) G for Fatty... you could end up with a forward group like:
Newhook-MacK-Rants
Lehky-Fatty-Nuke
Wood-Kampf-LOC
Ideally you'd push one of LOC or Wood to the 4th line, but even as it sits.... Newhook gets a run as a pure 3rd wheel top 6 guy. If he can't cut it there, you upgrade that at the deadline (plenty of wings are always available). Lehky and Nuke make space for Fatty to work (worry about a finisher on that line though). The 3rd line is speed, effort and defense.... and occasional dumb play that you have to live with. The 4th line can be backfilled with guys that get left in the cold on sub $1m deals. Plus Pavel and Meyers give some options too. Pavel has a good chance at being a great faceoff and PK guy from the get go. Won't really add anything else.
Defense with this pans out to:
Toews-Makar
Byram-Manson
___-Malinski
Dermy
It rushes Malinsky into a role and there is injury risk with Manson. This type of roster though, should give room to add a very solid LD. Try to find a younger guy who is a 4/5 or a chaser that is willing for a 1 year sort of deal. If the deals come in cheap for Wood/Kampf, Gavrikov would be a nice add. If they don't, try to get a get a Cup chaser.
There are holes in this roster, but it can be made to work within the cap. It also leaves flexibility for moves. If Newhook doesn't work, trade him, a first and whatever prospect for Guentzel or DeBrusk. If Manson gets hurt, grab whatever physical RD is out there at the deadline (and don't re-sign them). If Fatty doesn't work... you might be F'd... Which is the whole crux of the offseason. The 2C spot has to get a solution and honestly has to work.