I had read this with a degree of panic last week, as we had booked to stay in a PI in central Manchester on Friday and taken the early check-in option as we needed to dump our bags, get over to Piccadilly and meet our son and family off the train from London. We've done early check-in with Travelodge a few times without issue, but never a PI.
We arrived a shade after 1100, and saw that the automatic check-in screens said we needed to speak to the staff member, who then had us checked in and happily heading for the lift by 1105!
One minor gripe with their Portland Street hotel, though. It is another one arranged around a central void, so the walk to rooms at the rear is quite lengthy. Still, I suppose it means the further you go along the corridor the less guests need to pass your door at night.
There was some noise from the narrow street behind us - bottles being tipped into bins and a rather early call by some sort of utility vehicle - but I suppose we didn't expect much peace in a 24 hour party city!