Just signing Carlson in general I would think. Let's take the low end and give Bowey 1M, Kemny 1M, Carlson 8M and Wilson 3M. That's 13 of your 15M in cap space available already without moving Orpik. You would still need to add a DSP and Beagle replacement and a backup goalie- that gets pretty tight with only 2M or so wiggle room.
I'd easily retain on MDZ as he has only 1 year left, but the cost would go up. At 50% that would still save the Capitals 4M in cap space and likely allow one of DSP or Beagle to be retained. I wouldn't be expecting a 1st instead of the 2nd but maybe your 4th to replace ours?
MDZ @50% for Orpik, FLA 2nd and WSH 4th.