Hi, if you look at the Alleyns coach service/school bus info it will give the pickup time for your local stop and that is how long it takes!!!!
Likewise any route planner/satnav/TFL route planner will give you times - or get on the local bus/get in your car and give it a go yourself!!
Re other kids locally, there will be a smattering of local kids in the same school year as them but with a broader admissions area that will obviously be far less than in a local state school with a limited catchment area. When children go to a school further away they will have fewer local friends - it’s basic geography.
Hi suspect you want soothing words re distance and friends - really is they will have to get up earlier, will get home later and have fewer local classmates.