agree it's more of a bandwidth problem than a wifi problem, 6 clients should be no problem for a typical home router.
True story, when we visit my parents a while back that pushed their network to almost a dozen clients and we had big problems on their old 5/2 plan (5MBPS up, and 2MBPS down). In the end the only solution was to upgrade to a 25/25 plan, all problems went away.