One of the ways to guarantee yourself free Wifi is to stay at a major hotel brand just off the strip. Typical business hotels under the Marriott and Holiday Inn brands abound in Las Vegas and the majority of them will offer free Wifi.
If you planning your vacation tip for US, Then new York is the best option for vacation trip. Las Vegas is best cite of New York, LA is nice if you stick to West LA/Santa Monica. Chicago is a great city also.