I started working at wordpress.com (Automattic) in 2006. Everyone was remote.
I was in the UK, a colleague was in Eire and everyone else the US. The colleague was (still is) a coder, I did user support. Communication was IRC. The effect for me was that I'd do my full day then stay online as the US folks started theirs. 15+hr days became the norm (I moved into tackling spam as well as user help) and on more than one occasion I'd just work through the night. ENTIRELY up to me, zero pressure, not even implied. I just like to stay on top of things.
Motivation? I was hired to do a job, so I did it.
At the time I imbibed a lot of caffeine but that was as much as addiction as anything else. Kicked that habit before I left.
It took some years but teams were eventually set by timezone +/- a few hours which was good.