You can turn off higher level location services at the OS level, but at the radio level the cellular network will always need a precise enough location to handle tower handoffs and timing issues between the tower and phone, as well as modern beam forming techniques where the tower "aims" the signal at the phone. The simple act of the phone communicating with a specific tower tells the phone where it is (sometimes with surprisingly high precision).

911/emergency services also use more low level location techniques, but I'm pretty sure those functions don't get called unless you dial an emergency number.

Turning off your GPS will not turn off location sharing to Google or other people, it will just fall back to using cell towers and wifi. Admittedly, it will be much more inaccurate, but it will still try it's best. You can also turn off wifi and even data service itself to save energy. Although at that point you might as well just turn off the phone.
But I wasn't talking about system level shutdowns. I want talking about in comparison to your standard level of activity. If you have your GPS on for anything like maps or anything else, you aren't going to see a noticeable difference with personal location sharing on.