Renting in London - Am I missing something?

Evening all - there have a number of posts lately on the buy vs. rent decision. I suppose this is another take on it, and a plea for a sense check.

I'm female in my mid-30s working in Finance in London (base £120k + theoretical bonus potential of £180k but in reality more like £60-80k). Husband works in Consulting (base £145k + bonus £50k+). One child and planning our second this year (would love more in the future). Combined portfolio of c.£700k (35% bonds, 60% equities, 5% cash) + combined pensions of c.£400k.

We own our current property outright (post-fees would expect proceeds to be c.£1.2m). We love our area but are already outgrowing the very limited square footage and no. of bedrooms. If we manage to have a second kid this year we need to move. I suppose I always envisaged us upsizing in London, stretching to a hefty mortgage (5 bedrooms in our area costs c.£2m) and committing to the work-life balance we already have (i.e., pretty intense).

Coming back from Mat Leave last summer I've had what I'm sure is a common experience - a real questioning of what I want to be doing with my life and how I want to live it. I've realised that whilst I value my career and enjoy my role I really dislike the culture and politics of my current organisation. My husband enjoys his job and is probably on track for partnership within the next several years. The thought of committing to a £5-6k per month mortgage + childcare to live in a city just so I can commute more easily to a job I don't love suddenly feels absurd.

But then I look at renting in our area and we'd be spending £7k at a minimum. We can't leave our part of London for family / care reasons I'd rather not go in to, but within 5 years I could certainly hope/imagine us moving out to the countryside. I would also love to move abroad (Hong Kong, Singapore, Abu Dhabi), albeit my husband is less keen.

My game plan as of now is to: sell the house, leverage our ability to pay c.12 months up-front to negotiate a discount on rent, and finance a chunk of the rent via a series of gilts with laddered maturity dates. At the end of the day, we'd still be paying a massive amount for rent but we'd have the flexibility to move and make decisions based on how I feel after kid number 2 / when I've had a chance to look for a new role.

I suppose I'm looking for advice or thoughts from people on:

* Whether or not I've missed something.

* How others have approached this situation (i.e., between kids 1/2 and needing to move home but not wanting to commit ahead of career decisions).

* Anyone who has rented in the £7k PCM+ range - did you manage to negotiate a discount and, if so, how much?

* Anyone else offered 12m+ rent up front in exchange for a discount and, if so, how much?