Depends on where you are going, whether you need to sleep in your and proximity of bike shops (even some fairly big alpine resorts are not well served with bike shops).
Having spent 7 month living out of my van whilst riding in the pointy bits of Europe, I think I was pretty lucky with the only purchases I had to make were brake pads, Granny Ring (this was the era of 2x + Bash) and rear wheel (the longish travel hardtail curse).
That being said on a 2 week alpine holiday I had a Charger damper start to leak oil out of the bottom of the fork leg on the first day, which was suboptimal.
Must Haves (assuming your bike is freshly serviced with new pivot bearings/bushings etc:
Mech Hanger x2
Spokes
Freehub body (if no spare wheels)
Chain
Cassette
Rear Mech
Shifter
BB
“Normal” Post + QR seatclamp
Worn In Grips
All the brake pads
Rotors
Brake hose and fluid
Fork/Shock Volume Spacers
Tyre(s) (you’ve probably fitted thicker casing tyres for the Alps etc so just bring he ones you took off)
Tubeless valves, sealant and tape
Extra spare tube
Aside from the tyres most of that will fit in a shoebox
If you have space:
Wheels
Fork/Shock (if you already own them)
Brakes (if you already own them)
Cheap Bar
Tools:
Your normal everyday riding tools/spares plus:
Decent multitool,
ball ended 4/5/6mm,
Torx drivers you might need,
Chain tool,
BB tool,
Bleed kit: brake bleed spanner, hose cutter, bleed cup, syringe, hose
Adjustable spanner
cassette tool
Chainwhip
Track Pump
DH Tyre lever