I'd take them to your mum's, maybe stay there yourself too.
I wouldn't trust five blokes you don't know that well to be alone with your cats. Some men don't like cats. Some are ignorant oafs.
They'll be safe at your mother's, and you can spend evenings with them so that they won't be too upset. Does she live very far from you?
Otherwise, a cattery; although this won't be a homely and, unless you've used it before, you can't guarantee the level of care they'll be given.
Never trust builder's estimates concerning how long a job will take; it usually takes double the time they say.