MikeFromTokyo

I might contact the GM in that case, unless I already had a contact at the hotel I preferred to deal with. I would not "lay out" past stays because A) a good Peninsula GM should already be aware and B) it's not particularly relevant.

Negotiation is very personal, but in most cases when I do negotiate upsell it is very shortly before arrival. I find that expressing too much interest, too early on might lead to a higher price being offered, whereas if it really is a last minute upgrade into a suite that will otherwise go empty, one can really end up with a good deal...

But, then again, I typically do not need upgrades, but simply want them if offered at an attractive price. If having a large suite will really make or break this birthday party, then your outlined strategy makes a lot of sense.

In any case, if a larger suite is available, and you agree on a mutually acceptable price with the hotel, then I think any good hotel - and certainly a Peninsula - should rise to the occasion and help make your son's special occasion a bit more special if they can.