Yes! We can surely book separate rooms in Kathmandu for your portion of the trip. During the trek we will try our best but normally the lodges have twin sharing and dormitory styled room instead of a single room. The lodges will provide a private room for one person when the room is free and additional cost is not required.
The additional cost is USD 70 per person for booking a single room in Kathmandu for four nights when booking for groups of two or more than two people.