Peaking for Strength-Endurance

Coach Thibs,
If trying to peak for a multi-day event with a mix of endurance and strength work, not knowing the specific events, what types of functional and metabolic prep could help someone be at peak condition?

I am 4 weeks out from a volunteer work trek, where I’ll be doing 4 days of heavy construction labor with guys half my age in a remote wilderness area. I’m a 42yo w/ looong training history, I had been thinking I needed to work on “GPP.” I was alternating A/B days:
Both A & B start with:
Deadlift 2x5 (a la Pavel/Dan John)
Clean and Press 8-12 singles, 60-75%, by feel
A days: Full body circuits, then farmers
B days: bar complexes, then sled

But last weekend after doing 2 half-days of demo and installing hardwood floors, I could barely move. Short of doing 4 weeks of construction work (SPP?) what types of methods would you recommend?