To hit 3 G/G we need a working PP, and I don't think we have enough PP skilled right handed players to pull off anything above mediocre in that regard.
The top 5v5 scoring teams Chicago and Tampa scored 2.25 5v5G/G. The Rangers had awful shooting luck but still managed a 13th place with 1.90. That should increase just by regression, and the personnel changes in the offseason should improve it even further. I could see them improve to something like 2.0-2.05 which likely puts us somewhere 5th-8th.
Now to the PP, or rather the 5v4 PP. Washington led the league with 0.833 5v4G/G, we had less than half of that (0.416) which put us 23rd. I won't count on a very big improvement, but let's say we improve to 0.45.
That would give us ~2.5G/G 5v5+5v4, leading Pittsburgh had 2.94 last year.
Add ~0.33 G/G from the other situations (5v3, 4v4, 4v5, EN, PS, etc.) and we get 2.83 which should put us somewhere around 6th-10th in GF.
With Hank and our D, that puts us into contention for highest goal differential in the league and likely for the President's Trophy as well.