So we've all been there, the choice between travel light or take with the hot shoe equipment and save some weight. There are a few choices here, also with high speed sync and gells the smaller equipment may be the right choice.
But consider this.
Dim lit room with pin spotlights from above. Rather than gell a light or setup an umbrella with a gell, how about take a monolight with a battery pack (or plug in the wall) that has a light which matches the room lights.
Simple, easy, what you see is what you get, and if I didn't have that it would have been a lot harder to do with a gell and small flash.
Oh, by the way, you only get 15 min to deicde what to do, how to pose the subject, light them, and try a few different places.