Local guide are the best for glacial tours and ice-cave tours. 

I recommend their "Glacial Discovery" Tour which amazing: 

The Ice Cave Discovery is a full day adventure in winter conditions and the guides’ favourite winter trip. Hiking  across the glacier, you will reach remote locations and beautiful features keeping our groups  small (maximum 9 clients).

In addition to a super jeep ride through the glacier valley, bridge crossings over glacial streams and visiting ice caves, hike on the glacier for 1,5-2h total. During this tour guests will visit 1 ice cave as well as a beautiful blue feature on the glacier, which is called ‘the Blue Rose’. Our winter 2022-2023 tour also visits the Sapphire Ice Cave and is a good option for those wanting to add a little extra to their trip
