You're welcome Rondy, that should cover what you had with Sky in regards to calls anytime. You would need to speak to the team for the cost for this and's it's worth checking if the additional usage this would allow would save you those kind of charges if you changed but then there is also the peace of mind knowing you can make calls whenever if required.
Be aware that (probably like other incumbent telcos) the VM Talk More packages only offer inclusive calls up to an hour, and if you run over that then the charges are the sort of thing you'd associate with international calls. If you (or another household member) are prone to long calls, you'll need to be quite rigorous to end calls at one hour and re-dial - this is very easy to say "I'll do that", in reality it's much more difficult if you're either having a great call, or conversely talking with somebody who's having a tough time.
Last month my wife made a couple of extended calls to UK landlines (one call I don't believe is accurately timed by VM, but can't prove), and for the balance of charges just for the part of those two calls over the hour was about twelve quid, a very significant chunk of my monthly bill.