In that case, you can do something like this:
Day 1: Delhi to Narkanda (HPTDC Hatu is a good bet.)
Day 2: Narkanda to Sarahan (HPTDC Srikhand, right in down and decent option.)
Day 3: Sarahan to Kalpa, en route you can visit Sangla and Chiktul.
Day 4: Kalpa, rest and sightseeing day.
Day 5: Kalpa to Narkanda or Theog.
Day 6: Back to Delhi.
September would be a good bet, with mostly clear views and good weather.
For hotel in Sangla,
@rameshtahlan would be a better source of info.
If you're looking for home stays, they too can be found. However, with a kid, a hotel would be a more comfortable option.