Capfriendly is weird to look at right now with our IR and LTIR situation.
Next season, including Ness (we'll say he's replaced with someone with the same cap hit) we would have 17 players signed at about 74.5M. Hossa on LTIR for this. Two additions will be Hayton and Soderstrom. 895k and 925k each, so we're at 76.3M with 19 players on the roster. 17 skaters and 2 goalies.
That leaves us with at least 5M in cap space (Cap will go up) to add at minimum 1 skater, and max 4 players. Let's say we want to be dangerous and carry no extras, we could hypothetically move Raanta for a savings of about 3.5M if we go with Hill or Prosvetov. That gives you 8.5M + the increase in cap space to sign Hall. Last year the cap increase was considered very small but was still 2M, this year Friedman said it's projected to go to 84.5M, a 3M increase. So this scenario leaves us with 11.5M to give Hall if the cap goes up what is projected.
Now being more realistic,
Say Hall signs for 10M, then you have 1.5M left. Move Oesterle, 1.4M is a lot for 7th D. Up to 2.9M in space. 10 Forwards, 7D, 2 Goalies.
2.9M is enoug to fill out the roster. 1M to Fischer, 1M to a 4C, 900k for an extra.
Or if you want more room, then move Grabner, love him, but 3.35M is a lot for 4th line PKer. Then you have 5.25M for 4 forwards. 1M Fischer, 2M Vinnie, 2.25M for a 4C and an extra.