As a veteran, your husband is entitled to stay at Shades of Green in January & September by showing his DD214.
Also, which I just recently found out after speaking with Shades, you can stay on disney property anytime of the year if you book through Shades of Green, you will received a discount of some sort, but you can't stay at Shades if that makes any sense! The offer they gave me for November was around a 20% discount at Boardwalk Inn.
Hope this helps!