According to this book:
The Lawn Expert. Dr. D.G. Hessayon,
the best time to lay turf is October or November, but laying can continue right up to February, provided that the soil is neither frozen nor waterlogged. You can turf in March or April, but this will mean regular watering when the weather is dry. Failure to do so will mean shrinkage of the turves and death of the roots.
The book says nothing about slow-growing grass, but I'll have a look around and, if I come up with anything, I'll post it here.