I see you used QGis. Last time I tried it there was no easy way of plugging a router. I switched to QMapShack. It's a bit more complicated to use the IGN service for the maps (whereas it works out of the box with QGis) but there are several options for routers. The offline one (Routino) requires downloading data but it works well. I use it all the time to plan 2-5 days treks in the French Alps. Having the actual elevation profile for a given segment is really useful.

Just thought you might want to try this setup for your next trek!