Probably about 50-50 overall hour-wise, but times-used is more like 80% wireless, because I use a BT speaker most nights.
Interesting, but I'd guess the opposite because I always use LDAC and sometimes ANC with wireless headphones and IEMs. Bluetooth, plus these other software features have to draw some power, whereas wired does not. Volume definitely makes a difference, but I don't know if or how it varies by connection. I'd guess also that it's a factor wirelessly more, if not only.
I should have noted that I always have Wi-Fi off and Bluetooth on, and turn Wi-Fi on only for occasional Amazon Music use.
Finally, my favorite M300 battery feature is how FAST it charges: no measures, but it's fast. I try to monitor it to not charge it to full, but it usually beats me.
