yeah - I did the same thing with a friends MI-FI system. Actually, once you get it started you can walk away and your LTE connection will continue to work.
All you need to do is borrow a WIFI signal to initiate the stream.
As for the work around I documented, I would really like to know the difference in data usage between streaming and downloading.
TiVo S2 (Retired)(lifetime transfer)
TiVo Series 3 (Sold)
TiVo HD (Sold)
TiVo Premier (2 TB Upgrade)
TiVo Roamio Plus
iPad TiVo app