miffster, I expressed from 2 weeks (following pro-BF MW's advice, as DS had no latch issues, had good weight gain etc), and my DP fed a bottle of expressed milk pretty much as you describe. One night feed, which gave me 3-4 hours of uninterrupted and desperately needed sleep. Occasionally I had over supply issues - boobs that were too big for comfort - but this was a minor inconvenience. And a price I was happy to pay for a little sleep, and to keep BF-ing rather than use formula.
Advice on expressing early on is so conflicted. You can basically find an authority to support almost any approach. I think to a large degree, it's sensible to play things by ear and not make any huge changes suddenly. And be aware that women who find it very hard to express will objectify their experiences, and tell you that expressing IS very hard, full stop. Not necessarily. It seems to vary hugely from mum to mum. I find it easy and fast. Luck of the draw.
Obviously, where there are existing big problems like poor latch, failure to thrive, then adding expressing and adding a bottle feed may well not help at all, but it doesn't sound like that's your situation.
One piece of advice my excellent MW gave me was to introduce a bottle before 6 weeks, if I wanted to have the option of using one - then use it once a day, or every 48 hours, just to keep DS familiar with it.
Thank god she told me that. Other BF advice was not to express or introduce a bottle til after 6 weeks. There are many posts on this forum from BF-ing women returning to work, or in other circumstances where they want their older babies to take a bottle, just once even, but their babies won't accept it.
At 5-6 weeks, it felt like DS was feeding almost constantly. I've actually looked back at the times I jotted down - to ask HV if it was normal! - and he very, very rarely went longer than 2 hours between feeds.
It did settle down later - and DS is over 6 months now, still BF, never had a drop of formula, and happily starting solids now.
It did get easier, a lot easier - but I do remember those early days as being awful, utterly, utterly exhausting. I felt like a prisoner, resented it hugely at times, and I'm not going to whitewash my experience to sound positive, cos frankly, I wish someone had warned me about those early days instead of bleating on about how MAHvellously bonding and convenient (convenient??! FFS) it all was.
Cluster feeding is the pits IMO because apart from going on for SO LONG, babies tend not to seem satisfied or happy. So you do all the exhausting hard work, and get a grizzly flailing crying baby in return.
One final thing - if your DS grunts, groans and thrashes around in his sleep, once he is lying down flat on his back, then it might be worth investigating reflux, silent or otherwise.
My fussy feeding light sleeping DS had it - various things, including simply lifting the back legs of his cosleeper, so his 'head end' was higher than his bum end, helped a LOT. His reflux appeared somewhere around 8 weeks, I think - and I ignored/lived with the symptoms, and his unhappiness, for a while because someone confidently told me there was no such thing as silent reflux. And as a first time mum, I didn't have the confidence to follow my instincts.
I hope things are getting better for you. I remain totally convinced of the benefits of BF-ing, and I'm very glad I am, but those early days can be bloody awful. Big sympathy.