I realise this will be a ‘it depends’ answer.
But based on your Amsterdam deployment;
If you had 100 simultaneous users checking the water level in their boats, feeding cats, or whatever would there be network congestion? 1000 users? 10,000 users? What’s a ballpark guesstimate for how many devices the network could handle?
Presumably, you could mitigate this by just increasing the density of the internet connected nodes?