Kathmandu to Kohalpur is 11 hours comfortable drive. There are many hotels around the town as per your budget category. Overnight at Kohalpur.
Start driving from early in the morning. Manma to Sukhet is around 2.5 HRS drive which is around 100 KM. And Surkhet to Manma, Kalikot is around 150 KM which take a full day to reach there. If we skip few places than overall the road condition is quite good. This is one the scenic drive of your journey where you will be travelling through SAL forest.
Start driving from early in the morning. It is only around 20 min drive from Nagma and road starts rough non paved till Rara Lake. Now you will be travelling by the age of Karnali river for 4 hrs and than through the village and Sallaha forest. After 20 min drive from Talcha Airport one small cottage can be see where you need to park your vehicle and walk for 30 min to reach lake. For seeing lake this is enough but if you want to stay in the bank of lake and enjoy the spectacular view of lake than you need to walk approx 1.5 hrs by the edge of lake and you will reach the hotel which lies in the bank of river. You also have option to fix tent at the bank of Lake.
Early morning breakfast and taking boat to explore the lake is a wise idea. It cost only Rs 700 per person for the long distance sightseeing by boat. In the day time you can hike upto the hill where you can see the best view of the lake.
Return to Manma, Kalikot by the same route as you went rara the day before yesterday. Overnight in Manma, Kalikot.
Start you day early in the morning where you can find many places in the way to have tea rest. If you start you day at 6 AM than you can easily reach Kohalpur on the same day otherwise you will be staying in Surkhet.
It is same way back to Kathmadnu. Option to drop you to Pokhara.