Personally I don't tend to wait for too long, otherwise I'll just get hungrier and hungrier and grumpier and grumpier, also if I'm eating before I go out well I often cant wait anyways without delaying everything (which just often isn't an option anyway)
Though note now with my CGM I can normally tell well before a meal anyways if I'm a bit high (it beeps at me if I'm above 12) and get it sorted before meal time, so only on sensor change day (where it can go a bit choatic) do I normally hit said problems, sometimes its a bit high before lunch on teh sensor change day but I only have an hour lunchbreak ... so I eat then
I have seen many in here will definitely wait though, I guess people deal with it differently though