Well I would not be worring too much about it until two/three days out from an event… although wouldn’t be touching booze a good week/10 days before… Then just the same meals and meal sizes but with more emphasis towards carbs over other food stuffs…Also I start to drink a little more water a couple of days out… (and have a bottle next to my bed, If I turn over in the night I’ll sip a little water)
Morning of the race (2/3 hours before start) generous bowl of porridge keep sipping the water and maybe a power bar and/or banana as you arrive at the event and kept sipping the water until the off.
Water and gels to power me round, not many mind as they can give me stitches, maybe 4 ?? taken at about 10/14/18/22.
Milk and meat once done… and then feed my carb cravings later in the afternoon/evening/next day
good luck