How to keep dumplings from quickly drying out
Dumpling wrappers are by nature prone to drying out. A wet towel will only work to a degree. If the filled dumplings dry out slightly, it’s not too critical (note that I wrote slightly), so temporarily covering them with a humid towel or putting them in a sealed container should suffice, but the wrappers alone will become brittle and unusable.

If you don’t have a bunch of friends or family so that you can work in an assembly-line, rolling just a few wrappers at time is the best way. How many will depend on your how nimble your fingers are and what kind of pleat you are doing. Maybe start with around five to ten and adjust accordingly. 

Then either cook all dumplings after you are done wrapping, or cook batches while rolling, filling and pleating the next. This will need some more time management and multitasking and it’s your choice which one fits your needs and general preferences.