I use my cell phone’s hotspot to connect to the internet for updates.
Since I usually move mine from one location to another, having the network settings not change is helpful.
Sadly, the only way I got this to work is to have it near my main computer so that I can log into Screenly and connect it to my hotspot. Since my hotspot does not alter it’s DHCP leases often, the IP of the Raspberry Pi doesn’t change between connections or boots and allows me to log in using a second portable device.
The short is that I have the hotspot on one device and use a different device to connect and control Screenly.