This is well beyond anything a countryside pootler like me will do, but I know that there are folks on here that like a big adventure. There's a really nice article on BBC Travel about the development of mountain biking in Nepal and its potential to hugely benefit the local Sherpa communities.
Anyway, I thought that folk might be interested.
https://www.bbc.co.uk/travel/article/20260130-mountain-biking-the-himalayas-in-everests-shadow
Very nice article and a truely great place to ride and experience. You should go and pootle among the biggest mountains on earth.
I did a similar trip last year with H & I Adventures. It was the most amazing biking trip I have ever done. Not just the biking but Nepal and the people. The landscapes seemed huge. 
The bridges are great fun riding over them though a wobble sideways will shorten your time on earth.
Mike at Mountainbike Kerala (really good guy) runs Himalayan trips too. Been to Kerala - which was tremendous - and I’m sure his Himalayan trips are equally spectacular