That's why they are churning out transport craft and building infrastructure to bride that gap.
https://jamestown.org/program/china-and-indias-border-infrastructure-race/
Read under China.
Yes there will be damage to both sides, but India will face utter defeat.
Do you understand how costly It would be for China to sustain a campaign in Tibet- What are the problems associated with such altitude, climate and geography- forget about man, even machines under perform and fail regularly-
India has to sit on the ridges and make sure the standoff situation for 5-8 years with a minimum presence of 400-600 thousand Chinese troops near Indian border- China will fall, I am not even talking about Tibet. For China to win they have to cut across Silliguri corridor with Tank and Mechanized divisions and mount a Naval Marine landing of 200-300 thousand troops in Calcutta or Bangladesh-
There's a reason China withdrew in 1962 war even when they had already won the territory they are so ferociously claiming even today- Tawang and the region around that was captured by China, yet they withdrew- In 1986 when the Indian troops again crossed the line and took positions on Sumdorong Chu they choose peace and negotiation and Indian demand of keeping that zone demilitarized was accepted-
Interestingly Sumdorong Chu is on the eastern ridges opposite to Namka Chu which triggered the 1962 war when Indian troops occupied that position- Indians troops as of Today is in far better positions near Namka Chu and Sumdorong Chu, In the event of war these positions will fall quicker and they will be in a position of creating another valley of death in the Tawang region as they already have in Sikkim region WRT to Chumbi valley thanks to the higher positions at Nathu la, and Dokh la- Place where current stand off is going on-
I would advice you to open the Google map and see the regions and geography, Indians are at disadvantage in Daulat Beg oldie in Laddakh sector and Tawang, rest of the places our troops are in good positions- As of Infrastructure the roads are of the class of what you saw during Kargil war or better, you would remember Indian troops mobilization during that war and how fast It was done-
In 5-6 years there will be rail connectivity to both Tawang and Leh laddakh- Chinese rail is presently at Lahsa which is 200-300km from the Indian border- The closes Chinese airfield is also 200km from Indian border-
We have Y-20 strategic transport from now on, since it's made in China we can build this by hundred, and you can be sure that our supply line will have
FedEx overnight service.
The one who keeps their combat plane flying high, with greater loads and for longer will maintain Air Dominance- Geography suits India here-