Hi,
I will assume here feast is a once-in-a-great-while thing rather than a regular habit.
I would eat my breakfast as normal, I would eat lunch at the usual time though on the light side (especially if lunch may be your main meal of the day). If you go into your feast in full starvation mode, guess what? Your body will agree, and in infamous feast and famine mode will store up the energy from your feast very efficiently (read
too efficiently into fat). I would simply eat earlier in the day as normal and treat your feast as an anomaly, which is what your body will do.
Post feast - I am usually extraordinarily hungry the next morning. Where I may sometimes put off breakfast for a while, I usually have to eat when I get up. This is where you really need to stick to your usual breakfast because you will want more, or at least I do, and maybe more isn't really needed.