@vinc14 A ski touring route is nothing more than a rough sketch that takes into account the destination and available terrain. Deviations from the route are normal, as the best way to ascend or descend is constantly being re-evaluated based on required effort, perceived risk and reward. What may work for biking or running (staying on a predetermined route) cannot possibly work for real ski touring, and when it does, it is the exception rather than the rule.
For example, a flank may not be traversable due to unstable stratification, and the detour over the ridge must be taken. The tour I did yesterday was a prime example of this: avoiding avalanches on sun-exposed slopes as temperature has increased the last few days and chasing remaining powder on the northern slopes. In addition, there were several ascents and descents that made it impossible for the watch to track the route and remaining distance/altitude difference. Your idea of using the location and elevation of the end point to show the ascent and distance remaining simply does not work under these conditions.
In such situations, you need to know the most important points along your route, their altitude and distance. Also, you should bring the official topographic maps to aid in navigation. Your watch can help you with your current altitude. It is up to you to do the math or do the estimates based on the terrain.
The only alternative I see is using POIs to navigate. Bute a data field that displays the elevation remaining to the POI or as part of a bearing navigation display is unfortunaly not available, AFAIK.
