Pre-cutting Cigar Question

Hey fellas I have a quick question. First, the situation:
I am making a 4 day travel to London via flight(Ryanair to be exact). I plan on bringing a few cigars because I can't quite afford some of the ridiculously over-priced cigars in London. I can not bring my cutter due to only being able to bring a carry-on bag. I will be storing the cigars in a small 5-cigar travel humidor.
Here are the questions:
Should I cut the cigars the day of my trip then stick them back in the humi until smoke time, or should I buy a cheapo cutter there and cut when the time comes? Does cutting a cigar several days in advance of smoking drastically effect the draw, burn, or humidity level?

Thanks!