Our fryer is an electric one, and goes up to 350. We run it full-tilt for the potstickers. We’ve also made this with ground turkey, or a mixture, and have never had a problem.
You need to do one or two, and cut them open and test, to get the timing down. Don’t do too many at a time, and let the oil come back up to heat before doing more. As noted in the original post, my friend does them in a cast-iron wok on the stove, a few at a time. You can probably get the temp up a lot higher that way.
-JT, not a scientist :-)
Frying is very intimidating to me because of the whole temp thing. My mom visited with us a few months ago and we fried some shrimp on a propane burner outside in my cast iron dutch oven. It took FOREVER to get to correct temp, cook a batch, get it back to correct temp, etc. etc. They were delicious, but what a pain.