My two cents on next year. With DG gone, I think the team will really rally around MK and TC. I fully expect Keene to be the starter next season. He did a very serviceable job this year filling in for DG, and many of the mistakes he made could be chalked up to lack of experience. TC may be the more talented of the two, but he will still be a freshman, and not sure if he needs time to adapt to college speed. But either way, I do think that Gus would find ways to get TC into games in order to get him some valuable experience.
I think our defense will continue to improve, and will be creating all sorts of havoc on opposing offenses next year. We may not be seeing the 30+ points on a regular basis that we saw under Frost/Heupel, but we won't need to with the way our defense will be shutting down other teams. Get used to a lot of 24-10 type of wins.
I think we have a pretty decent chance to get back into the NY6 next year. Not as an undefeated team - but as a solid 10-2 or maybe even 9-3 team. I don't see Boise bouncing back next year. Our primary competition for NY6 will likely come from San Diego State, or if someone out of the Sunbelt or CUSA runs the table with an undefeated record.