In October/ November, in north India, you should visit Kausani, 40kms north of Almora.
At Kausani, stay at Krishna Mount View. The views of Nanda Devi,Trishul and Panchchuli peaks from your bed (yes, amazingly true), is astounding. The food is fabulous and the weather, perfect.
In south India, I suggest Munnar, and Thekaddy, since Ooty is too crowded and commercialised. At Munnar,stay at Mahindra's Resort.
An even better option is Lakshwadeep Islands.... Yes, Why not? Afterall, a honeymoon should a memorable holiday in a mind-blowing place ?!