.... since you mention this topic about motivation.. I've been reading some about this topic (motivation) and what leads to having a good amount of it. Based on that, and partially own experience, I've come to believe that motivation is basically more dependent on brain chemistry than "willpower". Many studies show f.ex the effect of having either too low, or high enough dopamine, norepinephrine in our brain, and it's very clear that dopamine plays a very important role in generating this mindset we call for "motivation" .. of course.. you always have the "normal" way of creating this motivation through the repetition of the desired action and having the reward it should bring in some way, thus creating this link between action-reward... but creating this link is not always as easy as some want to propose in those motivational books, specially if the person is having very low levels of these chemicals.....
So, whats the solution...
In my case, I've had very good results using nootropics.. specially a combination that can target specific neurotransmitters in the brain responsible, among other things, of creating this balance that naturally creates an energetic, focused, motivated mind state. I dont want to appear like I'm trying to sell anything here.. but if you're interested in more specific info. I can provide general info. so you can read more, and eve. make your decision.
At least, for me this has worked very well..and not just to wake up early if so I choose, but to have the energy, focus, motivation to go through the day doing all the tasks I've planned, and work extra those days it may be needed.
Hope this helps !!