FYI, roaches are the longest survived organism on earth...not much takes them out short of a nuclear bomb. Which, in turn, would probably not kill them, but mutate them into some huge man eating creature!
It will take them a while to die off. That being said, dubias need warmer temps to reproduce. They say 85-95 degrees F. So, you shouldn't have any of them reproduce, to be safe, I would let your house get a little cooler than that during the day temp you gave. Also, you should spray around/under your fridge, washer/dryer, and dish washer. Around AC/heater inside as well if central air. These spots are generally the warmer in the house and would be where these guys will probably seek refuge first.
- Justin