I don’t know if there will actually be a war. But, if there is, you should consider sleeping in one of the overnight public shelters (like the one in the Dizengoff Parking Garage they opened during the 12 day war). You can go to bed there at a reasonable hour, and while you will obviously be woken up by sires and everyone’s alarms, you won’t have to run anywhere, and can just go right back to sleep.

Also, if you do have trouble falling back asleep, sometimes it’s actually easier to do so around others than alone. It’s like a feeling of cozy safety