I used an "M" helmet there for many years before upgrading to a "SA" Carbon Fiber bucket. Your helmet will be fine.
There are no motels real close, there are a couple lowend places in Charlestown (Days Inn etc.) afew more in Frederick MD, and there are a couple decent Hampton Inns in Winchester VA, but that is on the far side of Summit from you.
Have fun, it is a great program at a great track.