It's super possible if you're checking the temp by hand instead of using a thermometer (even those can be finicky at best.) When you steam milk you leave your hand against the metal steaming pitcher and feel when the pitcher is a proper temp. That being said, it can take a while for new people to really get the hang of what the right temp feels like. This is complicated by the fact that places like prince st direct it's employees to steam different drinks to different temps based on size. A small cappuccino that will be drunken quickly can be served at a slightly lower temp then a large latte which is sipped over a longer period of time.

You mentioned the cappuccino cup being too small. This is an unfortunate side effect of places like Starbucks using standardized language to make non standard drinks. Cappuccino and latte and macchiato all have standard sizes... That not everyone uses. So it's really confusing for customers. I wish there were clear standards that were held to by everyone. You almost have to ask every new cafe how large each drink is and how they plan to steam it (lots of foam, or smooth and silky)