I also have this setup and SFos on Gigaset GS5. Similar battery performance. I did a roadtrip last week with navigation (starting with about 90% battery) and after 5&1/2 hours navigation was down to 65% or therabouts. Works for me.
And, yes, I often turn off wifi. I never go over my Data limits and 4G/5G is much more efficient for some reason.