Stan,
It isn't a meat trip for me. Early in the season grouse and woodcock hunting is largely a spectator sport. I get a few shot at birds, but, it isn't terribly important to shoot at every bird, and won't happen anyway. Bringing one gun is a very good idea, it lessens the chance of theft, either from the vehicle, or the tin shack I stay at, which, is a possiblility in the neighborhood. My Dad taught me that bringing only one gauge of gun was a great idea, I've just taken it to the next level with but one gun.
The 20 is a recent gun, comfortable and easy to carry. As I said, I got some birds, missed some others. I could have done worse.
I'll use a gun with more open chokes this year, but, a little secret between you and I is I doubt I'll bring a bunch more birds home, and, I'm OK with that. I haven't killed more than a brace of grouse in a day in a long time, more than enough for me. Catching dinner with Lloyd, and the time spent afield with him, and the pooch and sometimes, our kids, is maybe just a bit more important to me than how many I got. It isn't that I'm lazy, I just enjoy the whole trip, and I honestly could make it work without a gun if I had to.

Best,
Ted