Data usage viewing downloaded shows thru a personal hotspot

[Cedarsrip]

At our summer place the only internet available is through cellar. So I download shows at home to my iPhone and watch them at the summer place. I can watch Netflix through an HDMI cable. But for other services I use Chromecast. I can get it to work with two phones, one of them providing a personal hotspot. 

My question is this: is 100% of the downloaded data actually passing to and from the internet with this method so I am actually using a ton of cellular data and not saving anything through the downloads I do?

[Byteguy · Accepted solution]

That is right, Chromecast will always stream data from the internet.   Even when you have the file downloaded to your device.

You are not saving anything by pre-downloading.

[Cedarsrip]

Thank tou. I had a suspicion.