I've flown with my daughter several times, but I've always with my husband. This time, however, it's just the two of us. (He's meeting us at our destination and flying back home with us)

I'm planning on taking a flight that takes off just before her bedtime. I'd get to the airport early and let her get out as much energy as possible before the flight so she's basically exhausted and will want to sleep. I'll change her into her jammies before the flight, nurse her as we take off, and pray to God that she'll fall (and stay) asleep. I'm also thinking of just keeping her in the Ergo for the 3-hour flight, since I *hope* she'll sleep. We're both used to the Ergo, and sleeping in it from time to time, so I'm thinking that could be the best option.

I'll be visiting my mom, so I won't actually need to take her car seat (she has the exact same one I do, so I'll borrow it while I'm there.) I'm only wondering if I want to shell out the (ridiculous) extra bucks and take her (ridiculously heavy) car seat just in case she doesn't sleep in the Ergo, I could put her in the car seat and hope she'd sleep there.

Has anyone been in this position? Good plan?