Sam you?ve got your answer, you going to have to basal test every night, as it seems you don?t get problems when you are testing!
If you take a look at this link
http://www.diatribe.us/issues/13/learning-curve.php it will show the criteria needed for achieving a good quality basal test that produces useable data.
If you read this is explains why last nights data is really unusable, as you made corrections so this would have influenced your night time basal. Also it shows why it isn?t a good idea to do your next night time basal test when you go to London, as you will be out of your normal routine so there will be no knowing whether any of the readings you get, have been impacted on from earlier events... (I know that when I do any long distance driving, that it?s not only the driving I need to adjust my pump settings, but I also have to adjust my pump over night, due to a time lag that happens over night or face a hypo)
Another tip to good basal testing, is avoid slow carbs, and high fats foods, keeping constant carb amounts for meals for several days before the basal test.. This makes it a lot easier to see what is happening with your food and then when it comes to the basal testing it?s a lot easier to see what is actually happening..
I understand that you do shifts as well, so here you need to concentrate on each shift separately building a separate profile for each shift... I?ve managed to fine tune my profiles for work that they are actually tailored to what Kennels blocks I?m working in (so I have 3 work profiles in total)
While you collecting data, it would also be wise to keep an eye on whether you wizard perimeters are set correctly, as if you?ve used data that was fundamentally incorrect, then you?ll never going to achieve good control, as in reality a pump can only do what it is told, wizards can only calculate the information it?s given if this is out, then any calculation will be also be out..
And sadly there isn?t any fast track method of collecting the necessary information... It?s a slow methodical collection in all the years pumping, I?ve not come across a pumper who?s gained good control using any fast track methods they?ve dreamed up!