I have the same problem and do an overnight mash, using Brew In. A Bag. I set up at dough in just before bedtime. Then I wake up early and fire up for the boil. I wrap my pot with hot water tank insulation and ii find the tempo will drop about 10 degrees by the morning. In BIAB you do a full volume mash using full amount of water, it ends up a bit thick so I just leave in the and heat up for a mash out which thins it out before I remove the grain bag.
Let me know if you are interested and have any questions. You can also search HBT for overnight mash as there is a thread for the topic. It works quite well with no ill affects on my beer.
I am also looking into no chill brewing as another way to speed up/break up my brew day.