If it were me, I kind of think the rebuild will turn more towards let's seriously compete once all of Staal, Lundqvist, Shattenkirk, Smith are either traded or their contracts just end.
Between now and then,
I sort of expect them to just continue to sell off the pending UFA players they are not going to extend and really Kreider may be the only one I see them doing so with, perhaps Fast, Name, Vesey depending on what they are looking for in their next contracts weighed against what they could be traded for.
I think they'll look for some hockey trades too if they can find some higher level players that become available for whatever reason. Probably also have their eye on some already drafted prospects or younger players they like.
Panarin, (any significant UFA signing really), I think they will certainly show interest, yet I also think that will come down to his contract demands and have to be weighed against what other offers he gets from other teams and is willing to accept. I don't think they will just blank check him, yet if he really wants to play for the Rangers they can probably work something out where the Rangers still have some flexibility within that contract.
However if the Rangers truly have to compete with every other offer he gets I would think they have to draw the line somewhere as it's kind of questionable where he fits into that timeline as he'd be about 2 years into his new deal right as all of Chytil, Lias, Howden (Hajek, Lindgren) are needing 2nd contracts, and he'd be about 3 years in when all of whoever makes it from the 2018 draft needs new contracts, and so on and so forth. (if that is their timeline)
Overall I am hoping they are attaching their timeline to the 2016, 2017, 2018, 2019 and maybe even the 2020 drafted players (even those they traded for) more so than they are worrying about making the playoffs with Lundqvist, Staal, Shattenkirk. If by the time all those draftees/prospects make it, should most of them make it, if Zbad and whoever, say Kreider are still going strong and need new deals make the choice then to retain them as the vets.
As I type all that it really puts the onus on them drafting, devloping, trading for, signing some legit game breakers, all coinciding together within a timeline where most are in their primes all at the same time. That is going to just have to come down to faith that management is really on point, and hopefully some draft lottery luck I guess.