Replying to Dakine Concourse Double & Flights (+K)

I'm shopping around for a skibag and suitcase specifically for airtravel, and I'm trying to figure out the most efficient combo, the less baggage items the better imho.

I've read the Concourse double packs a lot of stuff, but can it pack everything for an entire week, incl. all clothing?  If it can't with two pairs in it, can it do so with only one?  Or do I definitely need to get a suitcase aswell, f.e. the 65L or larger 100L split roller.

+k for info!

thanks