DS2 (6 months) is hugely inconsistent in his sleeping habits. He has been capable on the face of it of sleeping through from a few weeks old, but there were a series of things that stopped him doing it - feeding problems, bronchiolitis, a lengthy stomach upset etc, so he switches between sleeping consistently 7.30 through to 5.30 and going back to sleep till 7 after a feed, to waking anything up to 4 times a night to feed. Now he does this fairly regularly even if there doesn't appear to be anything wrong.
We have been on holiday for the last 2 weeks (in the UK so no time zone issues) and he started sleeping through again on day 2 - occasionally waking for a sip of water or to have his dummy replaced, but not feeding or staying awake. In the second week he once again reverted to waking 3 times a night for food (literally overnight change as usual - one night sleeping 10 hours, the next night waking ever 2 or 3) and also not wanting to go back to sleep after about 5am.
I know I can get him back to sleep but it will take about an hour of effort, but after a couple of nights this will probably break the waking pattern and he will (barring illness etc) go back to sleeping through. DP thinks this is terribly mean and that it is me trying to enforce some GF-type routine. I should say that we have never been remotely routine based - both DSs have been fed on demand, nap when they are tired, in a sling if necessary etc.
DP keeps getting up with him when he wakes at 5am and saying "you get some more sleep" which is obviously very well-intentioned and kind, but it is getting very difficult to keep saying to him "I don't want more sleep right now, I want the baby to NOT get into a pattern of getting up at 5am" because when the holiday is over I will be on my own with 2 kids Tuesday to Friday (he works in London), one of whom is waking 3 times a night and is hell-bent on getting up at 5am. I would rather he just stuck his head under the pillow and let me get on with settling DS down. I can't seem to get him to understand that some babies need a bit more work at getting them to sleep - DS1 started sleeping through at 7 weeks and never stopped, so as far as DP is concerned, if DS2 isn't doing that then it is something we are doing wrong.
What I actually think is going on is that DS2 is a determined little bugger and we need to adopt a completely different approach.
So any ideas on how to stop the constant sleep regressions? And how to get DP on board with persisting with an approach?