Download the SpeedTest App from your Apple or Google Play store and test it at the house. That will give you good indication if that will be enough for you.
We are a family of 5 with about 25 internet connected devices, although not all at once are used. We stream all "TV" related content through two Rokus, plus various tablets, phones, game systems, and computers. We have 75Mbit cable service from Comcast and typically get 85-90Mb download and 12Mb upload when checking via Speedtest. This plan includes 1TB of download data per month and Comcast claims we typically use 300-600GB. I would expect that you will be using similar amounts as my family based on similar uses.
Cost: data is expensive via cellular in the amounts you plan to use. Check the fine print on cell provider unlimited plans. Many are speed limited at a lot lower than 100GB/mo uses.
