Changing Wifi SSID

Easy: configure your phone hotspot to serve the node. When you get to the location, connect a laptop to the same hotspot and configure on-site.

Easy: get a travel router. Configure the node to connect to it, also your laptop. Connect to the local Wi-Fi, use the laptop if necessary to get on their Wi-Fi.

Less easy: obtain a small monitor and keyboard, take them along and configure on-site.

Less easy still: configure your laptop with Internet Connection Sharing and connect it to the node, configure on-site.

Which of these makes sense to you?

Pres W2PW