I wish that were a question with a simple answer. It's really quite nuanced. My network is 300up/20down and I have even more devices than you, with no stress at all. Part of the reason for that is the router technology. With MU-MIMO on modern routers, you don't have traffic stacking up like you used to. You easily could double, or triple the amount of devices you have, and probably won't even notice a bump. But how many is "safe" just really depends on a ton of factors. That still alive packet is called polling. Some devices do more polling than others, and that varies from firmware to firmware. Devices that poll several times a second, can add up if you have tons of those. Devices that poll once a day are not even really noticeable. It also depends on your network architecture. What kind of through-put your router can do, your modem can do, your smart hub can do, etc. It depends on things like do your AP's have dedicated back channels to the router. There is a lot that effects the max capacity. But, you're safe to rock with what you have until you can't. I don't think you have anything to worry about even if you double or triple your WiFi devices.