Due to the pressing concern of the boat sinking we're still in initiative...kinda, but there are no enemies on the lower decks.
With a dash, Sam and Leaf
could reach the top deck and the open air on their next turn, but given the likelihood of an enemies up there not sure that's desirable. Your characters would be aware of this, so I feel comfortable giving that 'hint'.
So, to skip over "I dash this turn" x5, does the party want to spend a turn or two assembling at the bottom of the stairs up? Trickle up turn by turn? While you COULD try scouting ahead with Grepha, every round of scouting is a round closer to icy cold.
It's going to take Grok about 3 rounds to get to the bottom of the stairs, so I don't really want to spend a week or two on that. Might kill the interest a tad :P
Initiative order:
Grepha: [23]
Sam: [21]
Grok: [17]
Leaf: [16]
EA: [15]
Vala: [14]
???: [12]
Caeyln: [9]
EV: [4]
ES: [4]
Senna: [1]