I mean, sure, if you're hosting 1000 of your closest friends, I can see the potential issues. But for you, and a small party, it shouldn't be that awful.
Large groups, close together, are the largest load factor on a server like this because of the explosion of interrelated event broadcasting. "Oops, Lulzmage just cast Blizzard on a pack of 10 toons in the midst of a two 40 man raids attacking Orgrimmar." WoW has never handled them well, and it's fundamentally why they rarely do "world events" anymore, even with the modern sharding tech.
But a hundred folks across Kalimdor killing boars one on one, eh, not that big a deal.