Is it possible to play on the bnet servers at a Holiday Inn? Last time I couldn't connect. Do I have to set up a hotspot with my phone? Help!

As long as the internet has inbound and outbound signal I dont see why you cant. Maybe firewall issues?

Places like a motel will have some type of security/firewall issues. You will need to open a port which would most likely be impossible. Hotspot with your phone is your best bet. I've played D2 with my phone wifi and didn't have any issues... unless you are up in some mountains with like 2G/E connection lol

Just check your firewall, Something is wrong with the ports of firewalls. I can easily play using my Hotspot.