To have the best of both world at home and while I travel my iPhone is on the minimum storage capacity and iPad is 128GB.
At home & out and about there’s no problems with internet and even if I’m travelling within the country the coverage is pretty fine almost always for me. So I can pretty much stream anything. While travelling my phone will need to be somehow connected to the internet so either way I’ll figure something out, like an international data pack or a local SIM card.
My WiFi only iPad becomes entertainment hub mostly while travelling where I’d have downloaded the things I need / want during my trip. Some movies / songs etc. And if I want to use the iPad for work then it’s a simple matter of connecting to the hotspot on my phone.