.... and reporting back.

I was able to walk between terminals 5-8 (as I recall there was a locked door in the corridor to 4). Quiet, nothing open, but some pax (few) in all terminals, waiting for flights.

Not uncomfortable. Reasonably quiet (unless too close to a loudspeaker), not too cold (some terminals seem to be heated, some not). Most seats (T7, T8) were padded, no armrests - lying down on them was fine.

I'd do it again.