It sounds like you have done a fantastic job of building up a great base and applying the more specific training (ME and Z3-4) for this trip. Something to consider with regards to this style of training is that the gains from an extended block of ME training will last for about as long as the block lasted. If you’ve done 8 weeks of ME 1-2x/wk and added in some Z3-4 work as well you’ll feel the fitness gains that came from that for about 8 weeks.
Because of this I would drop altogether the ME workouts during the taper. You might consider doing one short 30-30 workout late this week. Otherwise reduce volume 50% this week and another 50% next week.
You are fit. Now you just need to be rested before you start what will be a demanding week in Chamonix.
I’ve used this ME block strategy with hundreds of athletes over many years and during the taper period after stopping the me it can take up to a full 2 weeks to see the maximum performance gains. You are carrying some fatigue that you do not even recognize right now.