this place sounds spectacular.

Doi samer-dao  means "Mountain in the same level of stars" It's top point of Srinan National Park in Nan.(around 80 km away )

I just wondered if anyone has ever visited Doi samer-dao and camped overnight there or stayed in a guesthouse in Nan.

Apparently it's a really nice place to see the mist and clouds below you and particularly at sunrise and to see the stars at night.

I would be interested to hear anybody's feedback because I'm thinking of visiting there.

I would be renting a car from Chiang Mai.

That Eastern edge of Nan has many interesting sites. I don't recall the mountain you refer to. I have camped in Doi Phu Kha and Sri Nan NP's. If I remember correctly, the road goes through Sri Nan NP and the campsite is at a high point.

 

Be aware that Nan has become extremely popular with domestic tourists. Do not even think of going there any time within 3 days of a public holiday unless you are planning to stay at least 500 m from a road. This will cull out around 98% of the herd.