In my opinion, we can move on from some of the aging defensive players (or tag and trade - if everyone else in the league can do it, I wish we would too!) but keep Brady and retool the offense. The defense is young and can adapt. The offense can't really evolve beyond the pieces it's given (as we saw this year). Move Van Noy, we have plenty of young linebackers that we drafted with 3rd, 4th rounders. Even Hightower might not be necessary right now with Bentley behind him.
Our group of CBs is the key position group on this defense. With them the best in the league and locked up, we have leeway to mess around elsewhere. Harmon, Chung, and even Brooks can pick up the slack for McCourty and we've already been experimenting with others playing safety, such as Jones. I have no concerns over that area. The pass rush is dependent on our secondary. Our guys rarely win 1 on 1 like the premier pass rushers in the league do - it's often stunts up front, coverage sacks, and blitzes. Do we really need expensive pass rush specialists in our linebacker and DL core such as Hightower to do that? - could be something to move on from. The defense was already the oldest this year so it's something that needs to be a tough call situation.
Keep Brady - his physical skills haven't yet declined, just his decision making has been a bit off. Hopefully it improves in playoffs. OL has been good for 2nd half of season and the running game improved with it. Andrews back and Wynn improving will be big deals. The big area of emphasis is TE - and the FA class is perfect for TE. I'd honestly prefer to go two competent TEs over a big splash like Hooper or Henry. Ebron is young and could be on sale and we would need a second guy to play in front of Izzo next year.
WRs aren't too bad on paper. Edelman was great this year when considering the entire season. N'Keal Harry and Jakobi Meyers should have extra juice. Those three by themselves aren't a bad trio of WRs - really it's been the complete lack of a TE that doesn't open up any space. Sanu has been a good WR2/WR3 his entire career and I see no reason to start believing that he won't get over his drops problem.
This isn't a rebuilding year going into next season. It's just a transition. Our team is really old and we have all the young pieces in place (DL we have our 3rd and 4th rounders we drafted 2-3 years ago in Wise, Rivers, etc. for example). But for me, the defense is the area to take from, because there is MORE young talent stuck in backup positions compared to the offense, and since the cornerbacks are locked in.