My MIL has just told me I'm really irresponsible and shouldn't risk it.
DD is 6 and will be in bed. Neighbour's dd is very responsible and at least one if not both of her parents will be in all evening and have told her if anything does go wrong to come and get them - semi detached house so only a few seconds away. We'll be less than 15 minutes away and on our mobiles.
But MIL has just put fear of God into me. According to her they will l both be dead and the house burnt down by the time we get back