I guess you could do something like that if you don't need any computers and other devices such as an AppleTV, at home, to access the Internet. Otherwise you would need to setup a hot spot from your mobile device and as far as I know that has a data cap associated with it. My ISP has no data cap. I would really love to reduce my monthly bill by $80 by doing something like consolidating cell and home internet.
Yes, I would setup my phone as a hotspot and let all devices have access to the phone hotspot. I believe if you purchase tmo unlimited, hotspot unlimited is included... I'm going to give it a try in the next week or so... The only place I most likely run into trouble is the 3 IP wireless cameras (1 is HD) that are recording to a NAS...I think that will be pushing it.