Normal working time for Quikrete 5000?
I did the pour today.

It was 50° F with about 80% humidity.  It looked like rain so I mixed by hand in plastic tubs on tarps inside a garage.

Quikrete recommends 6 to 10 pints of water for one 80-lb. mix.  I used exactly 7.5 pints for each bag, which gave me a very stiff mix that held its shape until vibrated.

I mixed four bags in two tubs and it took a good 20 minutes by myself just to get those two 160-lb. tubs mixed thoroughly enough using a hoe and shovel.  Then I was able to completely fill 3 of my 7 molds with these two tubs.  Filling, vibrating, placing mesh, and screeding these 3 molds took another 50 minutes.  I was able to catch a long enough break to clean tools and tubs.  Then I mixed the last two bags in one tub and finished the last 4 molds, which were smaller and already had rebar and mesh secured inside.  This took another hour.

Short answer:  I easily had over an hour of working time.