I originally intended to do seminars in multiple cities, even outside the USA, if there's enough demand for it. I enjoy traveling and always saw myself doing that eventually. For now we want to start locally to see how it goes, since arranging things in other cities would be more complicated.
As for vegan options at Vegas buffets, you just need to know where to go. The Mandalay Bay and the Luxor have some of the best vegan options. Excalibur's is among the worst. The fruit selection at the Mandalay Bay is especially good, including strawberries, blackberries, and other decent choices. At the Luxor on weekends, there's a full salad bar, fresh fruit, dried fruits, hash browns (cooked in oil), bagels, oatmeal and cream of wheat (both made with water) with cranberries or raisins, and usually a couple Asian options like a stir fry.
Often my family and I go to the buffet brunch at the Red Rock Casino, which is 5 minutes away from our house. They have similar options to the Luxor but with more Asian items. Last time I ate lots of vegetable nori rolls with pickled ginger and wasabi. They also have a vegan mango sorbet for dessert.
Generally the higher quality buffets will have plenty of vegan options, so you won't have to go hungry. The days of the super-cheap Vegas buffets are long gone though. A good quality brunch runs close to $20 now.