I have 3 lvl 6 players, who are transporting a relic. The Warforged Druid and Vulpine (Homebrew Race, Think Fox People) Artificer will be considerably late to the session, leaving the Crocidilian (Homebrew Race, Think Crocodile man) Barbarian (Who is my Older Brother) and a handful of NPCs (Half of which don't stand a chance in a fight) to safeguard it.

Virin, the Barbarian is the captain of the boat, which can move on land, and it'll be 3 in game months of travel before reaching the Capital.

I need a lot of encounters, of which I have plenty ideas for, but there's one problem:

The Only Player That Will Be On Time Is The Barbarian, Who is prone to ignoring most encounters, especially concerning encounters that give money, as he has acquired a huge stash of Gold Bouillon... Help?

He's not likely to stop for anything, so I'm trying to brainstorm an excessive amount of encounters, just so it won't be too boring.

Eesh the session starts in less than 6 hours.

EDIT 1: I'm not worried, but I just want to be sure that I'll have plenty to occupy the single player with until the other two stagger in. Also we do the sessions online on Discord, if that helps...

EDIT 2: The continent they are in is similar to Faerune, if that helps.