Hi AC.
As you are a Type 1 the NICE 2010 guideline levels are as follows:
Fasting (waking).......between 4 - 7 mmol/l.
2 hrs after meals......no more than 9 mmol/l.
I would say that the level of 12 - 14 mmol/l is not what you need.....certainly not OK !
The advice about reducing carbs is good for ANY type of Diabetic. As a type 1 if you reduce the carbs you may then find that your Insulin needs will also reduce. You just need to be careful by testing that you do not drop too low, into the hypo zone so it is better that the lower level is kept a little higher than 4 mmol/l. You need to find out why your level is much higher before midnight. Diet intake and/or dosage are usually the culprits.
I'm assuming you're on a MDI regime (ie you take a basal long term insulin like lantus or levimir and a rapid one with food )
If midnight is at least 3 hours since your mealtime insulin, your glucose level should normally have returned to within target levels,(except perhaps for very high fat meals which might peak later) I wonder if you are making sure that your levels are high at bedtime because your levels fall a lot overnight.
If your basal is properly adjusted you should be able to go to bed with a lower blood glucose level and your level should remain within 1-2mmol throughout the night
Obviously if you are using a mixed insulin then its a different matter as you have to account for the peaks in insulin action (though again I'm sure that people with experience with this regime could offer some useful suggestions)
It sounds like you're doing pretty well during the day. The only blood sugar level to be worried about is the high one at midnight. What time to you normally eat dinner? Do you still have some food being processed at midnight? If so, you could eat earlier. Also, just have a low carb dinner, so there's less chance of a blood sugar rise and also less room for error. I'm not sure what insulin regime you're on, but if it's not 4 injections a day or a pump, then ask your doctor about changing to one of these for better control.
Best wishes,
Katherine