MPU6886 runs at 3.3v, it has a sleep mode at 0x6B (R/W) bit 6 (mask 0x40). 1 for sleep, 0 for awake (not sure if it changes any other "power management" bits, check the manual sections 4.18, 8.38, 8.39, and experiment by checking 0x6B & 0x6C, putting to sleep and rechecking). It pulls only 6 µA while sleeping, though probably still listens on I2C. If your intent was to remove it's address from I2C, according to FCC docs, it looks like it might be the daughter board inside that can be disconnected.
ESP32-S3 runs at 3.3v, so it's powered by the SY8089, SY8089 pulls 55 µA quiescent.
OLED can be put into sleep mode, check M5Unified M5.Display.sleep() & M5.Display.wakeup(), backlight can be turned off via GPIO16
WS2812 uses 5v bus power on the Atom Lite, probably the same on the AtomS3's, 1 mA quiescent, cut the trace if you don't want it.