Infil for 500 km cannot be done with helicopters if the enemy is well-equipped. That's far too risky even over Southern Chinese mountain terrain. The helicopters would take four hours even if they were flying almost directly and few helicopters have the necessary flight radius at all (= some offshore service helicopters and CSAR/SF models).

A more reasonable approach is to infil the first 100-200 km as normal and then simply grab a civilian vehicle as a ride. The force density and threat of police checkpoints will be marginal that deep behind the battlefield.

A helicopter ride for 2x500 km is certainly neither necessary nor worth it.