That's better ... I don't know the Hemel end, but it looks like some nice lumpy stuff en-route to Oxfordshire!
I can heartily recommend a cake-stop at WaterPerry Gardens (a magnet for local club runs), great cakes, beautiful location, interesting museum of country curios. Between miles 46 and 47, Rowan Atkinson lives at Waterperry I believe.
Le Manoir at Great Milton is good for a snack (LOL), but is worth a little peek. You can have a wander around the Gardens if the staff are feeling generous.
Otherwise, I reckon you'll have a lovely ride!