We are entering the final preparation phase before the Engadin Ultratrail: if you haven't already done so, it is high time to study the course in detail. Study the altitude profile; you may want to take a printout with you or save it on your mobile phone so that you can check it on the way.
What do the first kilometers look like? Are they flat, does the run start with an uphill, does the course go downhill first? How do you want to start: will you run or walk the first kilometers? I recommend that you start slowly: the body needs to understand that you are asking something from him. Warm-up exercises before the start help to get it up to running temperature.
Also, take a close look at what the climbs are like: short, long, hilly? Depending on this, you will have to start the climb at a different pace. On long climbs, it is worth eating something beforehand. Also, study where the aid stations are located and what they offer. Not every aid station offers the same food. And take some favorite food with you: if you have a crisis, it will "pep you up". Assume the worst-case scenario: you may have crises along the way, so decide in advance what strategy you can use, for example visualizing your successful finish!
Divide the route into sections and focus on the next intermediate goal: this could be the summit of a climb, a village, an aid station, meeting friends or family, etc. Plan which sections of the course you can run a little faster and which you can recover on.
Now slow down a bit until your hopefully enjoyable day in the Engadine: don't overdo your training. At this stage you can't make up for missed sessions. And check the list of compulsory equipment, proof your material, and look forward to your run!