Potting makes a light drop proof. Zebras and Armytek are potted.
Since you are in Europe, to buy a Zebralight you could buy from Bob_McBob (he is in Canada), or you may choose to buy an Armytek, but see the caution below about its tailmagnet and the risk of using a Compass.
Cold weather Batteries:
The most reliable batteries for below freezing temperatures, are not rechargeable Lithium Ion 18650 nor 14500.
Non rechargeable Lithium, called Lithium Primaries, have the best cold weather performance. Examples of non rechargeable Lithium primaries include CR123a or the same non rechargeable Lithium chemistry in AA, called Lithium Iron (not Lithium Ion)
AA Eneloop is also more cold tolerant than 14500 Lithium Ion. So for best performance from you backup 14500 light, do not rely on 14500, instead use AA Lithium Iron non rechargeable Primaries, or Eneloop.
Armytek is a potted light, so it is drop proof. And they offer a light that can use 2x CR123a. That would be the most reliable Cold weather battery option, in a drop proof light.
Consider the Armytek Wizard C2 Pro Nichia, because it can use 18650 LiIon, and if that battery fails due to being too cold, you can replace the 18650 Lithium Ion rechargeable with with 2 Lithium Iron non rechargeable Primaries.
Armytek claims their 18650 light is good down to -25C. Suggest you carry several Brand New CR123a as backups. Bear in mind that dual batteries must have the same charge level, dont mix a partly used CR123a with a fresh CR123a.
Zebralight does not offer a CR123a light, they do offer an AA light (that can not use 14500 Lithiium Ion).
Magnets are bad if you use a compass:
One problem to be aware of, is that Armytek lights have magnetic tails. It would be bad to be wearing an Armytek headlamp, while raising a compass to eye level to take a compass reading, because the magnetic tail in the light, could interfere with the compass needle pointing to magnetic north.
That is why a Zebralight is superior to an Armytek. Zebras have no magnets that could interfere with a Compass. That is why Zebras are preferred over Armytek, by cavers.