Had a very enjoyable stay at The Old Vine.
As instructed, we arrived at the rear of the property at Check In and I collected the very helpful laminated parking permit (with very clear parking instructions and a map - much appreciated!)
Check in was via the bar (which was a bit crowded - Saturday afternoon) but we were shown to our very comfortable room by a friendly member of staff.
The room itself was large, with a king sized 'sley bed', and other heavy wooden furniture. The bathroom was a good size, although no bath.
The pub itself is fantastic, with excellent beers and wines on offer (not to mention the fantastic sausage rolls you can get as a snack).
But it's the location that makes the property - you are right in the heart of the (small) city and directly opposite the cathedral. If you have one day in Winchester, this is the place to stay!
The breakfast was hearty, big and delicious.
It must be noted, however, that as the pub is very old, there is virtually no sound-proofing. During the day, you could pretty much make out individual conversations in the bar below. This is probably why you can find packs of ear plugs in the bathroom when you check in!
That being said, we returned after last orders, and the hotel was silent.
Other slight grip - breakfast is only available until 0930, which on a Sunday morning seems a tad unfair.
In conclusion, I would recommend the Old Vine, but with caveats.