YOu could fence off a part of the garden for the dog to play in andput slabs down in that part. Then use the other part of the garden for planting, growing, mowing and the other gardening activites you don't want to miss out on.
Lawns and dogs never look good when mixed, IMHO.

As Beattie suggests, you need to work out how to keep the dogs off the grass. Then you can think about whether to reseed bare areas, or whether you actually would be better off returfing. Returfing can be done any time so long as the ground isn't frozen or waterlogged, but best left till March. Seeding best carried out in March/April.

Thanks for your help. I guess I'll just have to be patient and wait 'till spring.

Think and plan in the meantime, Rosie. Also consider what kid of grass you need: rhizomatous grasses, such as bluegrass or creeping fescue, are slower to sprout from seed than the ubiquitous perennial ryegrass, but once established, they will do a far better job of standing up to a rumbustious puppy.