If you’re getting a VAG diesel, I’d advise checking that it’s had its cambelt change (5yrs or 72k miles FWIR) - even at an independent it’s quite an expensive job. As far as DPF filter goes, we had an Octavia 170bhp diesel estate, and started to get DPF issues when we moved house and wife started using it for almost exactly the type of commute as you’ve described. The VAG independant that we used for servicing recommended that any VAG diesel should be taken for a half day motorway drive at sustained high speed at least once a month to avoid DPF issues! He reckoned that getting the engine hot for 15-20 minutes and then taking it up the revs a few times wouldn’t be enough to clear the cr*p out of the filter - he reckoned it needs long periods at high temperature that only a long high speed run can provide. Don’t know if it was just sales BS, but more recently, a Ford dealer told us that their DPF’s work at lower sustained speeds than VAG engines....hmmm
We flogged our Octavia for a petrol Ford:)
Having previously got about 170k miles out of a petrol Cortina, I would rule out petrol cars if you’re not doing long runs. I’d maybe look at ‘normal’ non-turbo engined models, rather than 3 cylinder twin turbo type things.
As far as Octavias go, we bought an estate, because we preferred the body shape, but the Skoda salesman did explain that the boot length and depth to the bottom of the windows is exactly the same as the estate - so I guess if you were open to the hatchback, it’d open up your choice a lot more.