Internet went down — backup options?

My apartment WiFi has been spotty this week and it nearly cost me a client call. What backup options are you all using?

What I've tried

• Mobile hotspot: Works but eats through data
• Cafe down the street: Reliable but noisy
• Coworking day pass: The safe option but costs money each time

I'm thinking of getting a portable WiFi device. Has anyone used one here? Which provider?

Also, any recommendations for apartments with truly reliable internet? I'll be looking for a new place next month.