Looking at flights for family next August from Newcastle to Basel and KLM are offering a connecting flight with only 40 mins at Schiphol. Would you/have you booked similar before? They say on their own website min recommended transfer time is 50 mins but they are still offering it. If you miss it they'll book you on next available flight - so in theory no worse off than if we booked the longer connection/later flight - but not sure how many would have last minute space for 5 in summer holidays!