You will still need to keep your Sky viewing card. If you stop subscribing on a Sky contract, you can keep using that card to watch 5USA, 5* and PICK TV, the so-called "free-to-view" channels. (All ITV channels are free-to-air).
Steve: What you have mentioned with regards to Sky having disabled your access to the recording / playback facilities on your Sky+HD has always been the case, but though you could have taken out another subscription (@ approx ?10.25 per month) at the time of cancelling your main one purely for the purpose of retaining the recording / playback facilities you have just lost, (and "only" those)
However, most decide against this taking this route by purchasing a twin tuner Freesat HD recorder (PVR) which is 100% compatible with Sky dish systems, the Freesat box referred to offering exactly the same facilities as a Sky+HD box, but subscription free!
On the subject of channels, have a study at the undermentioned link, running down the list of channels in the left hand column that you normally view, then checking along to the right under the Freesat column.
By the way, as far as Freesat HD recorders are concerned, Humax brand devices are one the most reliable types around.
If you do not have a steerable dish, most people don't, then the only satellites it can pick up are those located at the orbital position at which it is aimed, the Astra satellites at 28.2 and 28.5 degrees east for example. Most other satellites are not visible unless you are lucky enough to have a 'wide view' dish (which are rare due to the expense) or have multiple LNBs mounted side-by-side on the end ot the boom. If you do have those you may 'see' other satellites.
One solution might be a second dish, possibly steerable, but in the UK that will require planning permission and that is rarely given for a second dish on the same house. Having it on a ground mount would still require planning consent.
So if you have a fixed dish, there is little point in extending the listed satellites receivable.