Guten morgen Herr Cletracker:
The BV 206 idea combined with wide skis and a rigid draw bar is your best option if you cannot drive it out. Removing the tracks will place too much weight on too small an area and you are likely to break through the ice... spread your weight out like the wide tracks on the BV 206.
The Canadian army has tables for how much weight different thicknesses of different types of ice can bear. I imagine the Swiss army has similar tables so you may be able to get some advice from your nearest Festungs truppen.
Good luck and make sure you tie a cable to the carrier deeper than the water... at the end of the cable put a big orange float ball... if you have to scuba dive for your carrier in the spring it will be easier to find!
(I have dove to recover snowmobiles from frozen over lakes and rivers... BRRRRR!
)
Mike