For EMO to have full functionality, he will need to be connected to the internet all the time. Otherwise he will not be able to do many things (for example, voice command options you issue to him).
If you are planning on taking EMO out and about, I’d suggest using something like a portable modem / wifi router. This is what I use when I’m out and about and it works with my Laptop/iPad/Nintendo Switch/Phone etc and EMO as well. Something like this: (of course there are many kinds brands out there mine is a HUAWEI)
This way when you take EMO out and about you don’t have to connect to anyone else’s wifi network.