They have built up roads that wind their way up the ridge almost right up to the border (McMahon line) at multiple places. The closest road from that forward post is only ~15km.
(Armchair hat on) This area is perfect for a large scale salami slice operation, especially between now and the next year or two when we are still building the basic road connectivity. First step would be a make a dash to capture the heights - since they have roads almost to the border and we need to hike upto 10's of km, this should be relatively easy and probably can be done overnight with complete surprise. Then roll down the valley to the Indian posts end try to evict them (preferably without using fire arms), or at least pin them down. Then start extending roads to our side, this will probably take a couple of weeks, but don't let things escalate to a full scale shooting war. Pick a time that is most unfavourable for us like the monsoon when a lot of the roads get muddy or even washed away. After the initial skirmishes the one with the superior logistics, who can induct forces faster, will very likely win. With such a huge disparity they may be able to move in large numbers of troops and equipment even from their "mainland". And if most of these troops are able to cross over that mountain range into the valley on our side unmolested, they may not even need high altitude acclamation as the valleys on our-side are 6000ft or less. In a no shooting scenario I would go for a 5 to 15km slice, in a hot war I would aim to take 50-70km slice (i.e. most of upper AP).