When I go out, I have some presets in my Garmin Mini that I send to my wife. "Starting here, everything's fine, no need to reply" is sent as I'm hoisting the pack for the day. When I reach and select my campsite I send "Stopping here, everything's fine, no need to reply". THEN I go about setting up camp. If there is daylight, I try and check my headlight charge and recharge that when I still have light. Sending the stop message first lets the Garmin run for an hour to send the message. Wife knows she MAY reply, just not needed. So she has two fixed locations where I started and where I'm at. I don't have the tracking on but like every few hours as that runs the charge down in the Mini quickly. Once I'm settled in, maybe after dinner, I shut the Garmin down, shut the phone down and decide what to charge. Headlight can be charged in the morning while packing up (Remember to buy one with a Lock feature so it doesn't inadvertently get turned on in the pack and run all day). So the Garmin gets a charge if below 50 percent, then the phone, then anything else which isn't critical.
You can also switch the phone on and off Airplane mode when you reach tops of land features (Hills, mountains). I regularly hike at LBJ National Grassland (With the Garmin turned on and wife knows I'm out there). I don't bother turning the phone to Airplane mode as there is only about 1/3 to 1/2 of the place I hike with zero signal. On the tops of every plateau, I get one, two and even three bars of service.
Great idea on having ICE/Lost and your spouses phone number on your cell phone lock screen.