I worth peeling back and looking at the basics as 7 hours is a blooming long time
Water and something to drink from .....
Food (long life stuff ration meals / lifeboat rations that will survive the temperature ranges in the boot without going bad / Melting...
Toilet needs typical bloke I've got a small loo roll and a few bags.
Warm stuff let's be honest if it was -5°c it would be much more unpleasant blanket / sleeping bag wooly jumper hat gloves
Phone charger be it cig lighter type or power bank to keep the phone topped up so you can update the nearest and dearest...
And once your bored of Facebook and Jeremy vine a book to read wouldn't go amiss
It's ok having a winch / shovel / snow chains and a tow rope but realistically your more likely to be stranded on a motorway commute unless you live in the back of beyond
