...do all your prep work the night before - cooking dinner after dinner as it were. Then lift the filled crockery insert out of the base and stash it in the fridge overnight. The next morning, pull it out of the fridge, put it in the base and turn it on just before you leave the house. Starting with chilled food will add 1 to 2 hours to your cooking time...
...If you need to extend your time even further, consider getting a timer (plug). You should be fine letting your food wait 2 hours before the timer turns on the slow cooker - 3 if the food is straight out of the fridge.