I work for Royal Mail, this is what would happen in my office, although each area will deal with things slightly differently. The parcel will come in to the local sorting office as a result of the postcode. Given the lack of house number, the item will be given to the duty holder to attempt to identify the correct delivery address. If it is a regular guy then there is a chance they will recognise name and will get it to you. If it is someone unfamiliar with the duty then they will either write "pending enquiry" along with the date and it will be held over until the next day when the regular will hopefully be back.
The official procedure is for any item to be held for a total of 18 calendar days, so that would allow you to go in to delivery office (with ID and tracking info) where they would hopefully be able to locate parcel and put your house number on it. It is extremely unlikely they will hand the item over to you there and then for security purposes, but will arrange to have it delivered the next day, or a day at your convenience.
All that said, you could just as easily be unlucky and have the parcel arrive at the duty holders frame, who will take 1 look at it, see that it has an incomplete address and endorse it as such, which will result in it being immediately returned to sender.