Then work late and sleep in :-) I can't do a lick of useful work before 10 (which isn't great, since my job starts at 8:30), but I can cram 2-3 hours of good stuff in after my kids go to bed every night. Try different times to see when you're at your best. It's worth it to feel like you're making progress on something awesome.
And I've got to echo seiji - just get your product out there as quickly as you can. Let your coworkers look at it. Send it around. It may be that no-one wants to use it in its present form, but just looking at what you're doing may shake loose ideas and directions for the project that never occurred to you. Getting outsiders looking at your work is the difference between building something neat and building something great.