OK. You don't need to connect to Wifi to use the device. You can set the temperature by the dial on the front of it. The Wifi is kind of.... hmmmm.... how to put it nicely.... It's just there to make you feel good. You can cook without Wifi. You don't need to check up on the device every 5 minutes to see if it's working. Sous vide is unattended cooking. Just set it going and walk away.
I've been using my Anova for more than 3 years now. And since the first 2 weeks of playing with it I've never made use of the Wifi feature. The more you get comfortable with sous vide the less likely you are to use the connectivity.