Keep it simple, get a Beeline Moto II.
https://beeline.co/products/beeline-moto-ii
No need for power cabling, as it charges via USB and lasts > 12 hours. I've used it over a whole weekend of riding with no need to charge.
Battery impact on the phone is minimal, not irrelevant, but the phone I keep on the jacket so while GPS uses energy, the screen is actually off.
But, just as important is the fact that the Beeline app is extremely easy to use, the maps are very good with virtually every POI (Garmin jargon) available.
It's very easy to edit a route or modify it. This is often not mentioned enough.
Routes are saved on the cloud, so I can pull the iPad on the hotel or at home and edit route there with more screen for easier planning. When I go to the iPhone app, it's all there.
Also the puck (the actual Moto II device) acts as an interface to the app and you can skip waypoints with it, no need to take the phone out. Just recently they added the option to start a route from the device itself. They keep improving on it!
You can get voice instructions (turn by turn) so if you have a Bluetooth helmet you can get those right to your head. The puck does provide the map (of course) and a visual cue (blink lights on top) when the turn is to be executed.
IMHO this is a beautiful design and implementation of both: hardware and software.
For the record:
I am (was) fluent on BMW Motorrad Navigator V and VI and Garmin's BaseCamp
Also got to use and fluent on BMW ConnectedRide cradle and app.
If you're looking for simplicity, and classic looks, this is the way to go.
NOT affiliated to Beeline in any way shape or form.