Not sure I can cope with going back to an office - but cannot progress otherwise

[CloudsCanLookLikeSheep]

I work in a business support field, and whilst the first 10 or so years of my career were office based, I never really enjoyed it that much.

I then got the opportunity to go field based doing the same kind of work and loved it. I've done this the past 8 years and it's great to not be doing the daily grind/commute. I tend to either work from home or travel to other regional offices maybe 2-3 days a week. However it's not like a 9-5 as I can come and go when I please within reason eg if I get all my work done by 2 and have a long journey back I can leave at 2.

The problem is, it has severely limited career progression and I've gone stale in my current level. Where I currently work has no progression opportunities, as i'm the only field based worker in my department and the rest of the team are in head office in London (I cannot relocate).

There are not many jobs at the next level up which are field based any that are are extremely competitive. I got spoken to last week about a role which sounded interesting but it was 9-5.30, 5 days a week so I said no. I don't know if I can bear to go back into an office environment, but I also don't know if I can bear to stay at my current (junior-med) level when I crave progression and development.

Currently I have a great work life balance, the money is good (I get a car allowance which adds £5k to my salary) but progression is limited. Is it worth going back into an office environment in order to progress or will I regret it? It would be the easiest way to break out of my career rut, but at what price.