French cable car rescue
 

BBC reporting helicopter rescue of 48 people from stalled cable car line. anyone involved?

Looks like a Sécurité Civile 145, probably Dragon 74 aircraft, winching somebody in during the earlier part of the BBC's clip. Then the italian AW139.

I suspect it might be one person at a time at that altitude.

All have been rescued by twelve o'clock.
Two AW139's ships belonging to AIRGREEN Operator, Italy, winched out people to safety along with two Securité Civile H145C2.

Airgreen, an HEMS, Firefighting and Offshore OGP EASA operator, owns 5 AW139 and 4 Bell 412 out of a fleet of 25 helicopters including also Lama's, Astars B3p, H145 T2's.
One 412 has the Fast Fin BLR modification which is proven to be very effective in the higher Western Alps.

AirGreen has one AW139 based in Aosta just over the other side of Mont Blanc so would have been there very quickly.

What is the Altitude that they would be operating at while winching people out of the cable cars (ASL)?

3500-3800m

A struggle for the aircraft but also a pilot hypoxia problem during any extended operation.

Only for passengers trapped in the cable cars.