Griffin's position is apparently perfect. You either take the already overpaid offer of 5/80M or the QO. You choose, offers on the table till 31th.
Of course the best for the team is he takes the offer, even if it's overpaid. But if he's dumb enough not to take it and sign the QO, that's a horrible move for him, and not necessarily that bad to Cavs. Let's remember he will have to show work to deserve a near max contract next season. If he isn't motivated enough by his QO contract he chose to sign, he will be for his next contract.
If he signs the QO, Cavs can still sign him permanently when he's a UFA - regardless of what his agent says now, it's worth zero in 1 year time - and if he signs elsewhere, the TPE is lying there to be used. It's enough money to replace him. Bad news is at least an asset will have to go away along with the TPE, like Osman or something. But that's not a hefty price for him signing the QO.
In other words, Cavs are in a comfortable position here IMO. Just keep steady. TT is the one who has everything to lose.