> I don't want to lose a game because somebody in the vicinity turned on a poorly shielded microwave oven.
You shouldn't be using 2.4GHz anyway.
And there isn't much else that's likely to interfere out of nowhere.
> If you're going to all the effort of getting everybody together in person, why not do it right and set up a wired network?
Sure, go ahead and buy a bulk pack of cables, but I don't think it's going to have a particularly large impact on a generic small LAN.