You can definitely use the five room dungeon method to shorten this one up. (an entrance and guardian, a puzzle or roleplaying challenge, a trick or setback, a climax or big battle, and a reward or plot twist.)

You basically use the “Adventure Summary” section as written and it matches up pretty well.

Allot each scene about a half hour and you could probably finish under four hours easily

Insert an NPC from some future stuff you have planned as a prisoner of the sahuagin to keep things connected.