OK, there's bound to be other options. how many weeks are you now? If you can get your friends round this weekend to spend some time with DD that might be an option, you said it would only be 2 hours max - if they knew their DD was in labour and needed them, most parents would put their foot down and cover the journey in a lot less time... Your DD might be shy so it's not ideal, but it's an option if your PIL can't be reached.
Would the pre-school woman be prepared to take DD for 2 hours until your parents could arrive even if it was out of hours? It might be worth asking. Again, you need plans B and C if you know they are unrealiable.
2 hours isn't that far away to be fair, would your parents be prepared to visit say, every weekend for the 6 week period? That at least gives you that covered, then you've got the 3 days of preschool covered, (assuming if it's middle of the night your PIL's will just be at home, not out and about so reachable) it would only mean you're relying on your neighbour or friends to cover the 2 hour drive for 2 days a week. And again, while you think the neighbour might only do 30 minutes, if you said "look, my inlaws aren't being reliable, so I'm going ot have to call my parents, it's going to take them 2 hours to get here max, possibly less if the roads are clear, would you be ok with that?" most would say yes, it's not a long time.
Also worth remembering, you could call your parents and not need to leave for the hospital immediately, I started contractions at 6pm with DS, I didn't leave for the hospital until 10pm. Not ideal, but if you could hold out an hour, that's not long to leave your DD with someone.