This happens to me also - I generally follow the split-dose advice to get around it. Typically I'll do exactly as you suggested and have 50% of the total dose before eating and the remaining 50% at around the 1.5 to 2 hour post-eating mark but it depends on what exactly I've eaten (e.g. if high fat then I'll often need to split it into more than 2 doses).
I know that, for me, my total dose requirement for a meal is around 25 to 50% less when walking afterwards compared with when I'm remaining sedentary all night. For example, a Pizza Express pizza at the restaurant followed by a 20 minute walk after would be a total dose of around 6 to 7 units (split 50:50). Same pizza at home on the sofa would be more like 10-12 units (also split, although perhaps more like 30:40:30).
Enjoy your holiday!