Hi,
Does the car have an external key lock,(it may be hidden), if so have you tried this?
The external key lock may not have a mechanical linkage on this car, so it still may not work with a flat battery.
If the car is truly deadlocked, then the interior locks are disabled, so you will not be able to use a coat hanger on them.
Your options would seem to be:
Jack up the nearside front of the car and support safely. It may help to remove the front wheel. Find the main positive battery cable that goes to the starter motor( you may have remove the undertray, but if you're lucky it may be accesable through the wheelarch) If you get this far connect a pair of jump leads positive to the main terminal on the starter and negative to a bare bit of metal on the engine or gearbox. Then connect these to a good battery or a battery charger, this will probably set the alarm off, but you should be able to cancel this with the key fob and hopefully open the doors.
The other option is to hook the bonnet release inside the car with a coat hanger or similar, but I'm not sure how easy this is on the Saab. If trying to do this it helps to pry the top of the door out as much as you dare, a couple of wooden wedges help and don't really cause any damage.
It may be possible to reach the bonnet release cable under the car, but these are usually pretty inaccesable, made this way on purpose for security reasons.
Obviously there are any number of destructive options, such as breaking a window, but it would be best to try non destructive first.
Hope this helps
Good luck
Trevor