Of course you should ask you treating plastic surgeon first, as individual cases will vary. In my practice, if everything is healing as expected I would allow you to remove your compression garment for sleeping after 2-3 weeks. I would still want you to wear your compression garment at all other times except for showering.
I allow my patients to remove the garment for normal daily activities after 8 weeks. I do require them to continue to wear the compression garment for workout or strenuous physical activities for an additional two months. Total wear time of the compression garment is 4 months after surgery.