I think, you can keep the routine. If you let them sleep, I'm afraid they can enter "hibernation" mode.@Alex and the Redfoot what's your opinion? Should I keep ye routine? I mean To wake them up and give them exercise and food or leave them sleep and wake up when they want?
If they are still sleeping at 9AM, it's rather strange: usually they get up earlier to get some morning sun. If they sleep inside, try turning on room lights on at 6-6.30AM and then basking lamps 15-20 minutes later.