Introducing the bottle at 14 days old

Tomorrow I want to start introducing the bottle. I've been breastfeeding for two weeks and have established a good latch. I just want some help from my husband with feeding my son during the night so I can have longer periods of sleep. My son is currently feeding 2-3 hours apart, occasionally he'll cluster feed every hour or hour and a half. I still want to breastfeed as much as possible, the bottle is just for 2 or 3 feeds at night. How much should I be giving him during those feeds?