So how early should I get ready? 5am departure from bund area and about 1 hour drive to PVG?
I'm fine with Uber, but I find that People's Uber can be hard to get (compared to UberX) with the driver either not familiar with the area or taking too long to accept the requests.
5am departure is absolutely fine.
I'd say a cab offers more flexibility (as in, if you get up earlier and are ready to drive off at 4.45am already) and at that time of the day, shouldn't really be a problem to catch (especially starting at a hotel, where they can call you one) nor should there be significant traffic towards the airport.