I figured there was a reason you were on a 5/5 schedule, as far as you having to get up earlier to get a +11 I would wait and see how she does today when you get home before depriving yourself of sleep. If she doesn't bounce tonight and happens to give you a yellow PMPS then getting up early may be a good idea, because then you have a +11 to compare your +12 to and confirm that -for example- +12 is 201 and +11 was 160 her +12 is a rising number. Yes, if she gives you a low number at +12 you would not feed (stall) and check in 30 minutes, if the number is within 20% (meter variance) you would continue to hold the food and check again at +13. For your schedule, that means if the number is not rising at +13 and at least 200 you will have to skip the shot, feed her, and she may be high when you get home. If you feed, the number you see is partially a food spike and makes dosing difficult unless you know how much Mya goes up just from food.
I am not experienced at this, but some people do feed and then shoot a very reduced dose if they can't wait around...maybe someone else can tell you how that works, I couldn't reduce as I was already almost shooting on the zero line.
If you look at Kitten's SS, we had to stall on 3/7 am (she ended up rising by +13 and I shot her), and 3/10 am (she was still unshootable at +14, I fed her, and her pancreas kicked in), just to give you an idea of what it looks like/how to enter data if it happens. 3/10 is good to look at to see what a rising number is not, +12 163/ +12.5 179/ +13 170/ +13.5 154/ +14 161. Now I could have seen that 179 and thought I could give a reduced dose (i was shooting at anything rising at 180+), but with the 20% error 163 and 179 are really the same number. So I waited, and when I saw 161 at +14 I knew she wasn't going to be able to get a shot, so I fed her. If I had just shot at +12.5 I wouldn't have known that her pancreas was working and that the tests results for that day were not caused by the insulin. Plus if the dose were large enough, she might have hypo'd. That evening she did come up, and I gave her 0.05u (my cat is really sensitive)-her last shot (ever hopefully). The next morning 3/11 when she threw a AMBG (if you're not giving a shot the PS changes to BG) of 136 I knew she wouldn't be coming up enough before I had to leave, so she got fed and she's been doing it on her own since.