Well, even if some escape, B. dubia roaches need temps of at least 80 F to breed successfully. If your house stays much cooler than that you are probably fine. Especially in Maine where your winters are cold. You might see a slow moving escaped roach once in a while, but I really doubt you'll see any breeding. I live in SE AK and have had many escapes over the years. I've never seen young roaches, just some half starved adults who escaped the colony.
Now if you choose another feeder roach species make sure you know their temp tolerances to avoid problems. This is one reason the B. dubias are so popular as feeders...they are temp sensitive.