"See you again soon, then! Well, here they are." He hands two wax paper-wrapped packages over. One is thin like an envelope.

"You'll hold onto to the potions, right Deku?"

"Of course I will. They go bad in about a century, though."

The twins actually laugh at this. "I don't think it'll take us that long."

"Well, just making sure you know." Smile.

"So, you gonna make us a raft?"

"I'm working on some branches for you. You'll have to lash them together yourselves."

The twins don't mind. 

In that case, they have a reasonably good-quality raft and an extra large Deku Leaf rigged up as a sail by around noon the next day.

Time for goodbyes. Anything they should bring with them?

They've already packed all the relatively valuable and useful stuff. Nothing else.

"Goodbye everyone!" the twins shout in unison as they set sail.

The koroks that didn't leave for the Seeding Festival wave from shore. 

The current combination of wind and ocean currents give them the option of sailing on the spectrum between quickly North or slowly West.

Slowly west. They're in no rush.

The first landmass they see is a mass of ice, about four or five hours later. There seems to be something on that island that is producing a massive wall of cold wind.

They decide it's worth investigating.

There is swirling snow going everywhere, produced by a giant rock formation in the shape of a dragon's head. It turns out that their new bodies are at least marginally vulnerable to cold. They probably don't want to spend too long here.

"Is anyone here!" shouts Tabby.

No answer. If they actually climb from their raft onto the island and walk a bit they can see what looks like a treasure chest, frozen solid inside a big block of ice.

"Bet there's some cool stuff in there. If only we could get it unfrozen."

Is there anything they could light a fire with?

Hollo gave them a small vial of firestarting potion. One drop should do on any decent campfire. But it's cold and would be very wet as soon as they start one, thanks to the snow, and the only fuel they have is their raft.

It's starting to go from feeling unpleasantly cold to feeling stingingly cold.

They decide to try smashing the ice.

Nope.

Can they drag it back to the raft?

Nope. Attached to the island.

It's really really cold. Dangerously cold, probably. Maybe they should just come back later.