Just a quick one,
Is it impeccably bad to be late by a couple hundred KM for the first 1000km service?
I've never had a 'new' vehicle before so not so sure.
Are you voiding warranty by being late etc. etc. ??
Don't ask us, ask your dealer. They're the only ones that can give you the right answer.
Honda won't repair the engine under warranty if it's damaged after (or due to) missing a scheduled service. But they don't define "missed," your dealer does. It will be up to them to say at what mileage they consider the service to have been missed. So just give them a quick call and ask.
That said, if you're about to go on a long trip and want to know whether to take it in before or after, it's probably a better idea to take it in before even if you're still one or two hundred km short. There's the very small chance that they could catch a problem that would leave you stranded (or perhaps crashed) far away from home.