The reduction in VAT from 20% to 5% does not equate to a 15% reduction in the total holiday cost.
For example, a holiday costing £100 would have previously attracted VAT at 20% = £20, total cost = £120.
With the new lower VAT rate, a holiday a holiday costing £100 would now attract VAT at 5% = £5, total cost = £105, a saving of £15 VAT on the previous total representing a 12.5% discount on the whole cost (£12.5/£120)