There would be a good possibility of you going from a $300+millionaire to completely broke. That would be pretty damn heartbreaking and most likely suicide worthy(sorry if I offended anyone with this, but it's true).
I mean, you could always resell the Islanders if things get real bad.
I'd buy the Isles, but then I wouldn't really have enough money left over to throw a lot of money into the team. So I'd hire people who would work for peanuts, and I'd barely scrape the salary cap floor until such time as I could get a new arena and the rights to develop the real estate surrounding it.
Or maybe I'd just settle for Plan B, which would be to buy the absolute fastest car in existence, and then pay guys to replace the shell with one from a mid-80s, rusted out Chrysler K car, and then I'd drive around all day blowing the doors off d***s in Beemers who would then wonder WTF just happened.