First, I'd donate a BIG chunk of it to the zoo.At least $50 million. Maybe more. BUILD THE FULL AWESOME ELEPHANT EXHIBIT I'VE BEEN WAITING FOR! AND THEN DO MORE STUFF!
I'd also donate to several other causes I support.
Move to Washington. Buy a big piece of land. Build a house with a kennel and a stable. Have as many animals as I want. My stable would be attached to the house via a hallway (a glorified covered walkway). The kennel would be integrated into the house and designed to hold the dogs when I'm away or when I'm working one dog and need the others to chill, but the house proper would be totally dog-friendly and awesome, too.
Buy a Ford Transit Connect conversion for semi-local dog shows, and an RV for long distance dog shows. Campaign the CRAP out of Logan and get him his Ch and GCh. Do ALL THE CATs.
And, most importantly...invest it so I don't have to work for money anymore. Instead I'd work for free as a volunteer with zoos. And train service dogs for autistic adults and place them for free (including free team training and pay for all associated costs such as travel, food, and supplies...I'd even build a little guest house for the team to stay in during team training, since I'd only train one dog at a time).
Oh. And I'd go visit the Doctor Who Experience in Cardiff. Over and over and over. And go to all the Who-cons. I'd even make my TARDIS service dog patch design a reality so Logan could be in costume when he accompanies me
Basically...do all the stuff I want to do but can't afford to do.