To be honest, I would not be that fussy with all the data to start with.
I did a 202km ride last week and ONLY did the hill routes in Watopia and the whole lap in Richmond. This also was the the last day of my 14day achievement (60-80km every day, not bragging, just being factual here). It did take me just over 7.5 hours and 2396 m elevation.
My thinking is simple. If I can do 200km in the hills I will be laughing all the way to do 180km on a flat. Basically, if you want 100, train for 200.
Also, being in the hills is far more rewarding and keeps boredom at bay. That is quite important to keep mentally going. I tried music and telly and they do not work for me.
Finally, I never ever use any artificial drinks just bottles of Juice / water (50/50) and get the wife to supply me with slices of toast with jam or honey, maybe a musli at the 100km mark. (I suggested to get a cardboard cut-out of a car door to be more realistic with serving the drinks but she refused). Try to stay in the saddle for as long as you can (in my case 7 hours 40 minutes) as everytime you get out the chances for chafe increase.