It's not acceptable, Alan.
And even if you put up with it/get used to it, imagine if you ever sell the car privately in the winter!
If you feel it's appropriate/potentially useful, get it 'logged' by the dealer... and then pursue it. (See my paragraph below about how I went about that.)
Here's my experience with it:
Mine (GE 59/30000 miles) does it too in very cold weather since not many miles. The dealer has 'lubed' it on two occasions. First time - I was later told they lubed it with some silicone-based compound - silenced it for a year or more so that I thought it was 'cured'... but on coldest days this winter the 'creak' returned. Last winter the car wasn't used...
(Done for FREE, under warranty but I'd bet it's the work of just a few minutes.)
However the lube of a couple of months ago has not lasted. But it's amazing how noticeably quiet it is just after it's done. Because although it's most noticeable, by far, over humps, it's 'quietly' noisy all the time over all surfaces as the suspension works. It kinda fades into the background, I think, but nevertheless adds to overall front-end noise in cold weather, noticeable at low/round town speeds... and you insidiously get used to it till sudden improvement... just a shot of lube, say... SILENCE!
It has featured in my email to my dealer while under warranty and I'm assured it's logged in their system. (I checked that by asking over the reception desk while in for a service as to what's logged against my registration number. As follows: "Is there anything logged for my car Reg. Number?" "Can you read out what it says, please.")
So although my car is now out of warranty, I am fully expecting them to honour it as a fault reported while under warranty... and this I was assured they'd do. I must test that before the weather warms. This time I'll be pressing for new bushes (I think it's just two) hoping it's the rubber compound at fault and they've since revised the compound. Whichever way I want it 'cured'. Fingers crossed.
Creaking suspension bushes have featured on this forum before as a problem for several others - it's possible Honda UK know about it... It could be well worth contacting Honda UK if your dealer won't play ball.
Others may have something more revealing to add to what I have said.
It exercises me because it's otherwise a great car!
Do let us all know how you get on, Alan.