Hi, would appreciate some advice please. Am travelling solo with a 8 years old and a 13 weeks old next week long haul. Baby is combi fed, was thinking of packing some powder, sterilised water in a thermos and pre made formula bottles. Was about to do a click and collect in boots for the pre made formula bottles however it cost £4.50 just to do that. Does it really make things a lot easier to have the formula bottles after security ? Thank you in advance