Miami and OKC have so many mid sized salaries that they could pretty easily find a trade that fits into Miami's hard cap. The real problem is OKC wouldn't want all of those players back so they would have to find a 3rd and maybe 4th team that would participate.
I think this one would work (not sure if the Cavs would do it as it would make them a clear luxury tax team).
MIA - Westbrook, Dellavedova
OKC - Dragic, Waiters, Adebayo, Smith, Thompson or Henson
CLE - Adams, Olynyk