Our Mickey gets pretty nippy when excited, too, and it was much more of a problem when he had those crazy sharp puppy teeth, but now at 1 yr old he responds pretty quickly to "gentle" and "kisses", "no bite" prompts. But when he gets too worked up I have to just walk away because his first instinct is to mouth & he doesn't seem to know his own strength.
Someone mentioned winter activities - I would strongly suggest looking into getting a Varsity Ball (if you google it it should come up) - they are indestructible and big! Def for outdoor only. My guy likes to roll his around and try to stand on it - it's pretty funny. And it's almost the only time you'll hear him growl and bark - he gets so worked up with it that I have to put it away sometimes or else the neighbors will think he's vicious (he sounds it when playing with this thing!). BUT he comes in from outside panting and exhausted, so it's a nice alternative for him. I would caution, though, that bc the ball is really hard, he's knocked it into our rain spouts and caused them to fall down. So just be careful if you have anything outside that could get damaged.
