I don't think that defenseman is out there in free agency at LD, though. Brodie is a lefty but mainly plays and is better at RD. RD Tanev & Hamonic bring some similar stabilizing elements but with durability concerns. I'm guessing it'll be Dillon if they can manage to get him more on their terms. It isn't ideal and he'd need to be more toward that Edmundson $3.5M range. The closest fits in UFA may be Chara, Greene or Hainsey but neither are that guy anymore. I don't think Gustafsson is on that level all-around, nor Kulikov. Some of the UFA RD could perhaps work alongside Orlov but if a stabilizing LD is their target it'd have to be a trade (likely involving Kempy moving one way or another).
Mobility and size should be keys, hence bringing up Cernak or some other younger options. Barrie on a short-term deal could also perhaps work, esp. if they want to go more up-tempo. Orlov-Barrie would be an adventure but guaranteed entertainment.