Manali-Leh best way to travel

The safe option is spending the night around 3000 meters , in Sissu Keylong or Jispa . The HPTDC buses stop overnight in Keylong. Renting a full taxi gives you control over the itinerary -dont let the driver talk you in to spending the night at The Vomit Hilton/Sarchu , more than a thousand meters higher than Keylong.

Manali-Leh pointers here

I would recommend you to go for a private taxi as you have kids with you and whenever needed you can make a stop which is not possible with a HPTDC bus. Even if you hire a taxi, you can make an overnight stay at Keylong and then move on the next morning.

hi...well just to get rid from typical summer heat I personally prefer Nainital for the holidays instead Manali...pretty nice sunny weather and temperature remains ardound 15-20 degrees and pretty nice and lot near by places like lakes, tea-garden, sunrise point to explore and it's just 6-7hrs max from New Delhi...easy to go there however better to bookin things in advance as it's peak time and mostly places are full.
Manali is way to far and it will be 15hrs drive from Delhi...
All the places have same weather, plus Naintal is cheap and close by even by train...can give u more details if u need...PM me and will share some good localities around there to explore with least possible expenses...

Thank you Ady but our aim is to get to Ladakh and this is why we will be in Manali

thank you! it is all very helpful. We were planning to spend 3 nights in Manali before starting the trip and than 1 night in Keylong on the way

thank you but we definitely want to go to Leh by land and are planning to fly back to Delhi at the end

thank you! this is what I had thought...

.. morning flight from Delhi ...one can expect to experience some dizziness, headaches or even acute mountain sickness (AMS).

Dizziness and headaches , with or without
GI symptoms is AMS .

... the fact that Leh and most of the places in Ladakh are located at an altitude of 10,000 feet.

10 000 feet ... that would be Alchi or Ule Tokpo. Leh is almost two thousand feet higher , and this is an important difference the first nights. Very little is lower than Leh , Tso Moriri is one thousand meters higher , Pangong Tso seven hundred plus.

Re acclimatization in Manali : I still get surprised over how little this gives
, I once spent a lazy week there. Two nights in Sissu/Keylong/Jispa gives a lot more than three nights in Manali. On the nerdish side Vashisht is the only part at 2000+ meters ( 2070 ) . Town goes down to 1850 around the bus station & Tibetan temple.