Bernd-Cyan-Penguin Since yes u. A. was also a statement from me, I allow myself to answer. I used to do this story a lot in the past with a Series 2 (which does not have any cellular anyway), and it's definitely possible. Unfortunately, I can not tell you which apps need to be in place, or if they really are the bug, because I've never tried to remove most of the standard apps.
What happens if you activate the wallet with you by pressing the side button twice? For me, then the card appears in the middle, at the top is that she would be ready and below is that I can now pay with the watch. If this process works that way, I'd go one step further, and just turn off your iPhone for a second and then see if calling the map is just as possible. You should also be able to deactivate the WLAN functionality in the Control Center of the Watch, so that no network access is possible.
Although I'm not sure, I suspect that maybe this is the sticking point. Since even the GPS-only watch indeed has a WLAN chip, this tries to dial into known networks, if no iPhone connection is possible. This sometimes allows you to receive notifications or make face-time calls on the go, even though you do not have your iPhone with you and you do not have a cellular model. However, Wi-Fi networks with captive portals are usually impenetrable for the watch and, as far as I could observe, they can also "confuse" as they try to connect to a network, but this does not allow proper Internet access. Maybe there was a Vodafone hotspot near the cash register of the supermarket you were at? That could explain such an error message.
I would definitely do the "dry exercise" once at home, so you can be sure that it will work fine the next time at the box office. Otherwise, I've never had any major problems with my Series 2, so I'm hopeful that it'll work out well for you. I wish you success.
Edit: Ilan That's really not right. For many things, of course, a network connection is required, but not for Apple Pay.
Here it is listed again in a support article: https://support.apple.com/en-us/HT205547 Here is the payment with Apple Pay listed under the following heading: "When your Apple Watch is disconnected-for example If you're in an area without Wi-Fi or cellular signal, or your iPhone is off you can still do these things. "