I think you are probably right about the seniors, and I wouldn't be surprised if Thome decided to play elsewhere. That being said, if Adams, Mismash, or Bast would be interested in coming back, that would be a nice surprise.
Sanderson coming back was huge. Our blueline should be okay...especially if Bast decides to come back to play a year with his younger brother. If Thome decides to go elsewhere, then we are probably looking at the portal for a goalie, which would mean a significant question in net (although, heading into 2015-2016 we had extreme questions in net, and Johnson wound up putting together an All-American campaign). We definitely lost a ton of scoring (both high end and depth). If Adams or Mismash (or both) came back, the losses wouldn't be so terrible. We probably will need at least one solid forward from the portal, coupled with a Gaber-type surprise, to be a Top-10 scoring team next year.
While it is still way too early to really gauge, I think next season we are probably a 3rd-4th place NCHC Team on the good side of the NCAA Bubble.