I don't code Access, but logic tells me that you just need one more field: Status, which can have three values: Null, Kept, and Canceled.

Instead of deleting future bookings, set them to Canceled and exclude all but Nulls from your booking page.

Some day you might want to Query Client > Bookings > Canceled. It's good to have a permanent record.

nb: you might want to use "Future" vice "Null."