I haven't left any of our current dogs in kennels as we have been lucky enough to take them on holiday with us.
However, in the past I have left dogs in kennels and would say the best thing to help them settle is to take their blankets and a favourite toy or two with them - also maybe something that smells of you?
I know how you feel - my little Poppy has gone off with a friend today who is doing a grooming course and wanted to borrow her to groom..... Although I totally trust my friend and know that Poppy is going to be fine with her, I felt terrible waving her off this morning. And she will be home tonight - so you must feel even sadder
However, you are confident you have booked Murphy into a good kennel and are happy with them - I am sure he will be fine.
Think how delighted you will both be when you come home - he will be so pleased to see you so enjoy your break, but look forward to your home coming too!
Have fun, relax and enjoy. (I am sure you could phone the kennels too during the week to see how he is doing)