Extended bolus for pasta meals

Can anyone give me some advice on what would be a good starting point for an extended bolus to cover high carbs like a pasta meal.

Last night we had spaghetti bolognaise. Jess had 200g pasta with some sauce. I did a 50% 50% split with the second 50% being delivered over 3 hours. She went too low 1.5 hours after the meal (2.8 mmol/L) which we treated with 8g of glucose sweets and 10g carbs of orange juice. 3 hours after the meal she was 5.5 mmol/L (bear in mind she'd had quite a large correction when she went hypo 1.5 hours earlier). 5 hours after the meal she was 3.9 mmol/L which we treated with another glucose sweet. 9 hours after the meal her reading had climbed to 8.9 mmol/L which we did a bolus correction for and then 12 hours later she was back up again at 9.9 mmol/L which again we corrected for by which time it was breakfast time and her readings since have been in the 5's.

So I know the 50% 50% split is too strong to start with. Can anyone help me to make a guesstimate on what I should try next based on the readings I got last night?

That's great, thank you for taking the time to type that all out. I'll try it next at 30% 70% extended over 4 hours. It will probably need to be tweaked further but gives me a good starting point.

We're very much still in the experimenting stage but any foods that seem to give less than ideal readings I'll try the extended bolus on to see if I can improve them. It's going to be a long process I expect.

The types of food we eat and I expect will need extended bolusing are paella, risotto, take away fish and chips, pasta and pizza. I also think pastry like cornish pasties or pies may need an extended bolus and I'm yet to see what porridge does.

Last night we had take away fish and chips as I wasn't feeling well and hubby organised the supper. I'm hoping someone might suggest what combination to try next time as we didn't get an ideal result. Here are the readings taken:

7pm: 5.4 mmol - Fish & Chips, no sugar drink. 66g total carbs. 30% 70% split over 3 hours.
8pm: 8.8 mmol
9pm: 7.3 mmol
10pm: 4.0 mmol
10:30pm: 3.7 mmol - treated with 1x 4g glucose sweet
3am: 14.5 mmol - bolus correction
7:30am 5.8 mmol

I don't think the glucose at 10:30pm caused the high at 3am, one glucose usually raises her BG by 2-3 mmol. I feel the 30% initially was probably about right, perhaps it could go to 35%, but maybe the remainder needs to be extended over a longer period of time. What do you other pumpers think?