Before and after (albeit briefly) I was a real cereal diehard. My choice was 3/4 C Fiber One80 because the effective carbs in it (carb minus fiber grams) came to 15. Loved starting the day with a bowl brimming with grain, 1/2 C Silk Vanilla Lite, 1/2 C 0-fat yogurt (read added carbs), 1/2 c berries and 1/2 oz nuts. I recorded, but tended to turn a blind eye to all those carbs that shared the bowl with the grains.
It worked for a while until restricting carb intake to 70-80 and portion control resulted in upward creeping BGs. My first response was to cut back portions to 1/3 C, then 1/4 C, then to the "what's the point?" levels. Took a hard look at the minutia of added carbs and sugars and breathed a heavy sigh.
Can't say I blame you for wanting to hold onto that treat for as long as your meter says its feasible, but you may consider taking some "baby steps" by switching to cereals that have a more favorable carb:fiber ratio and playing around with what else you put in the bowl. I had to bid farewell to my love affair with cereal 3 years DX when I lost the good control I had and BGs suddenly shot up from less than 130 at all times to over 200 after high stress and a passing stomach bug landed me here on this forum, desperate to find ways to reduce those stubborn levels that refused to come down no matter what I tried.
Enter LCHF (Day 18 now). Not to goal yet (stress still playing role of major impediment) but BGs are now ranging from 96 (Yaaaayyy!!) to 136 and still gradually trending down. Feeling better, 10 pounds lighter and counting, and not looking back wistfully at the cereal bowl, now missing in action.