@leebee: You can email Mears and ask what time they'd pick you up and they'll e back. I've done this before. As long as it's not the day of the flight, you'll get an answer back.
If I had to guess, I'd say that for a 10 am flight your Mears Connect pickup time is going to be closer to 6 am than 6:30.
If you're registered with Uber, you might also want to create a Lyft account. Their fares are often less than Uber's, and I always compare before booking.