Owning your own home

I would also consider the time and cost of keeping a place of that size clean, warm and well maintained.

I don't know how it compares to what you have currently, but it looks to me that the effort and / or cost would not be insignificant.

I currently have a longish commute, and a 5 bed house with two kids in it. My partner also works full time and we struggle to keep on top of things.

but I just kind of fell for this place. Its beaut and there are some awesome schools nearby and it's got lots of nice green stuff around

Old adage is never buy the first place you see. All of the stuff you mention can be achieved under £1 M without screwing up your lifestyle to the same degree.

Don’t know what your work is but consider what it would be like if you had to get on a 7:30 am plane at LHR from that house.

I should say I have no intention of leaving London (born and raised) and the prospect of moving to the countryside/commuterland doesn’t bring joy to my heart.
Currently in the search for larger house with garden in south London and the only reason we’re considering being further out from our ideal location is being able to ride into work. Good transport links are for shitty days in winter and being able to get jnr around London easier.
Seeing more properties come back to our budget, which means we have more options than I thought we would.

As said above, kids change the equation toward being closer to family, know I’ve leant on my mum and brother in law to help out with jnr over the last 18mths and them being closeish has been a real boon.

I’d go and do a viewing at least. The house is banging and the garden and neighbourhood will probably be great for kids. I am biased though, because to me only zone 1 is London and the rest is a bit shit with the odd gem.

Wrote a response that was way too long, so have edited it:

Overall be rational and work out any move based on your set of circumstances.

These are some of the things that didn't occur to us, but have since been shown to be important.

1. Don't assume the benefit of family nearby. Sound it out first - what are their expectations vs. their capacity to deliver to your expectations?
   
2. Fertility treatment policy of the local GP and LHA - LDN GPs and hospitals will likely be good, outside will be a gamble. Check.
   
3. Friendship support network - for your partner. Depending on what type of baby miniloin is it could be vital for her mental health. How far will the close friends moving there will be, are they your close friends, will their lifestyles match a yours, etc.?
   
   

(FYI I've assumed your partner is female and she'll be giving birth to any children. Apologies for the assumption if that's not the case.)