As stated in my original post, cell phone service is spotty at the vacation property (although an Android or iOS phone would support Wifi too). I'm paying for broadband service at both my home and remote locations, though, and am looking for a way to "extend" VOIP service to the new property.

I do have Google Voice, and while it works with Google Chat, its call quality has been highly variable. Vonage has been rock-solid for me.