Well, the ideal candidates in Markstrom or Coleman will be too difficult to move given their contracts and MNC/NTC's. The others like Backlund, Lindholm, Dube, and Kylington, are either more valuable or will be cheaper to re-sign with still plenty of room for growth. Tanev is older and could fall off a cliff at any time but when he's going, he's a cornerstone of the defense. Zadorov is cheaper and brings much needed physicality. Andersson is untouchable.
So then there's Hanifin, a 26 year old top pairing defenseman making 4.95M for another season. I think his trade value might end up outweighing his on ice contributions, at least in light of what his next contract will be, i.e. 7M+. And whatever they get for him in return, whether it's futures or a competitive piece, the Flames can still ice a defense of
Weegar-Andersson
Kylington-Tanev
Zadorov-XXX
which should be good enough. Assuming of course that Kylington comes back next season