Last night the car that had been away for a few days continuously uploaded over WiFi for about 5.5 hours at 11Mbps for roughly 27GB uploaded. Maybe that does match up with a theoretical max
If the previous estimates of 1.5GB per video snapshot button press is still accurate (where it's capturing the last 30 seconds), that seems to allow 18 of these snapshots before overwriting. I did have to put the car on camp mode to trick it to stay awake to continue uploading.