We voted an an official 11 hour a week schedule for this year, where traditionally we've operated on an official 15 hour a week schedule. However, I came late yesterday and still put in 4 hours. We do whatever it takes. Saturdays start as a 7:59-3:00pmish during week 1, and by week 6 Saturday's meetings start at 7:59 and last until midnightish...
Mechanical, as far as your individual situation, it depends. If you're willing to settle for a box on wheels, you can get away with your current time schedule, and quite possibly less. If you want a six wheeled swerve drive capable of translating and rotating at the same time will launching moon rocks into a goal thirty feet away, then you'll never realistically finish. It's all about setting realistic goals. Just my 2 cents, you'll need more time. If you meet more now, and discover later you can meet less, great! But if you meet less now, you may find yourself wishing you had more time during week 6, which is never a good position to be in. This game will depend a lot on driver skill, so the sooner you finish, the better.