I took a 20 gauge Darne on the same trip last year. Semi-pistol grip and choked just a bit too tight for the work at hand. I only brought that one gun last year.
Typically, on a trip I am traveling to, I bring only one gauge of shotgun, and, if I am using a Darne, I only need one gun. They are more than reliable enough. Lloyd asked to see the "new" (to me) Halifax, and traded me some 2 1/2" 12 gauge for 2 1/2" 16 gauge. The Halifax 12 has short chambers. I no longer own a short 16. Good deal all the way around.
That made it a 12 gauge trip for me. The Darne with the bretelle got the nod.
Could be different next year. I have a Nitro Special in 16 with cyl and mod chokes, that could use a workout, a Winchester model 1912 20 gauge, and a Remington model 17 with two barrels.
Other stuff, too. I'm not thin on shotguns.

Best,
Ted