I would bring sweaters and also fleece jackets of some sort. My guys seem to like their fleece jackets much better - they are lighter weight and warmer. Just like people, you can layer if it's really cold out.
As for booties - they are generally only needed if there is snow and ice on the ground (and especially if salt and snow melt has been dumped on the snow and ice). I use Neopaws (
Dog Boots Shoe Neoprene Jackets Dog Sweaters NeoPaws) and they are GREAT! Not cheap, but are the best doggy boots I've been able to find.
I just ordered some more fleecies from this place -
Gold Paw Series : Quality Dog Products. They are really nice. I have two already for my guys but needed a couple of extra. Not too expensive and really nice.