Miraculously I managed to sort some of this out this past weekend.
In the end, what seemed to do it for me was a simple "PRAM zap", an old-school Mac "fix everything" trick which I haven't done on a modern MBP ever (that I can remember).
Anyway, try rebooting and holding down "command" + "option" + "P" + "R" all at the same time. It will reboot and play the start-up chime again. I usually let it do that a few times (three) and then allow it to boot up as normal.
Your display settings maybe off like mine was (...and a few others. I don't remember what PRAM holds. Maybe mouse/pointer settings?) but it seemed to clear up the wi-fi issues for me.
For posterity, I took many of the suggestions on the forums including uninstalling Adobe products, and reducing my start-up items. I did boot into safe mode and saw a marginal improvement. I also went as far as creating a new Network Location (sometimes those can get corrupted) and removing any Bluetooth connections. As I mentioned above, it seemed to be the PRAM zap which solved it.