unlimited mobile hotspot for tv and computers?

I agree with syaoran you can burn through 5 GB in no time flat. I had one of their little hotspot devices when we first moved here. I picked up one with 30 GB / month trying to keep the cost down as that was all we had. In testing initially I streamed a movie and in the background my daughter was doing a video call with one of her friends. Well, we burned through 10 GB in no time and I did not even watch the entire movie. So, you can stream all you want but beware if you exceed the data allowance then it gets expensive or it is throttled to such a low level it is useless. 

If you want to try to keep your costs down look into the T-Mobile home internet gateway solution in your location. That is $50/month prepaid and no data cap, no additional fees and no contract. You can try the phone as a hotspot but I think you will be disappointed. The gateway is a very good solution in most locations. If you are in a location where a strong, clean signal is not possible then cellular is not a good solution. Just my opinion. I did the mobile hotspot and it is way more expensive than the home gateway.  It ends up being roughly $10 per 10 GB per month