I read a little about the "cons" in Niven's writing. He seems to revel in them, what with his Irish Coffee and all.
That was pretty much how the first SF convention got started, just a weekend meeting among a group of friends who had been corresponding with each other, back in the '50s. It's grown since then... makes one wonder what future Entmoots might bring.
I liked the picture you posted, by the way! It reminded me of Upper Michigan... but then, almost any scene with snow and trees reminds me of Upper Michigan, lol...