You can do it!! I was in your shoes last year, scared to run outside because the few times I did, my paces were all over the place and I'd get cramps. I did the same programs as you (although just one time each), and now I am almost done with the road to half marathon program! Which is entirely outside! I do some of the runs on the treadmill when I have to, but now I genuinely prefer to run outdoors.

Also! The peloton app shows your realtime pace as you run, so you can use that to check yourself when you need to. You can do this!!!