The "bad weather" bypass to Camel's Hump is known as the Alpine Trail. However, you should actually also use the Monroe and Dean trail to Wind Gap at Montclair Lodge south of the Hump as the Long Trail is still pretty rough in this stretch. For solo cold weather hikes on the Long Trail I recommend having the guide book to know the locations of the various side trails and their destinations should the need arise to get off the trail itself.