Well, salvation lies within but Himalayas would be great place to go for peace. You can go to Garhwal Himalayas in Uttarakhand. Temperature is falling but Badrinath will be open until 17th November. I am returning from there as I type. Temperature is -2 so make sure you carry warm clothes.
North has beautiful options,go to Agra which is only 3-4 hours drive from Delhi, or you can prefer Chandigarh/Shimla,they are full of peace or you can go Nainital, Bhimtal,Tallital ,there are 9 tals or even u can think about Haridwar and Rishikesh which are more of religious place with beautiful scenic views
There are many places near delhi like the advaita ashram, mayavati, Vivekananda ashram, shyamlatal, macleodganj, dharmashala, and above all, I would suggest the spiti valley. its a serene place not touched by technology and crowd. though its elevation is a bit high, but do visit it if all physical conditions are compatible
Kasol anyday!! Go on a level 1 trek to near by village if you find some group and stay in a village without mobile network for a few days. I went on a Sar Pass trek when we had to camp in one of such villages named Grahan and trust me the feeling was amazing!! The locals were so kind and welcoming, we spent our whole evening at a local restaurant with the lady owner of that restaurant in her late 50s talking about how life was up there. P.S. make sure about weather conditions as they aren't good these day!! Hope this helps