Will type 1 diabetics wake up in the middle of the night if there sugar gets too low?

Depends. A diabetic with intact hypoglycemic response should wake up when bgs drop <70. However, if ur sugars are too low for too long, ur body gets use to it and your alarm may be set lower, for example...If ur bgs are usually 60's or you drop to 60's often, your body may not have symptoms until bg > 40's.
Usually. Many people with diabetes find that low sugars at night have different symptoms than during the day. Common symptoms for nighttime lows include: nightmares, thrashing, & soaking sweats. Sometimes people do sleep through nighttime lows and wake with very high sugars. If you think you're dropping at night check any time you wake up and feel odd, or set an alarm for a few hours before you wake up.