A reasonable guess starts with:
CLS (and R2 by implication)
ROLO
CHolo
Hoda
One new character that requires five other characters at 7* - one of which has yet to be released - maybe you'll need a new Empire - Hoth tag to unlock C3PO: Veers, Starck, Snowtrooper, and IPD would all make sense and be thematically consistent. Lord I hope not Wampa, too.
Could also do something Bespin-y - Lando, Lobot, Han Solo, OT Chewie + 1 more. There are some options.