London to Leicester (via milton Keynes)

I am not sure if this counts as touring as I am stopping off in a Premier Inn rather than taking a tent, but I am cycling from London to Leicester in a month or so over 2 days, stopping at a Premier Inn in Milton Keynes (it allows me to have bike in room)

The first part of the route (London to Milton Keynes) is here:
https://ridewithgps.com/routes/39048467

The second part of the route (Milton Keynes to Leicester) is here:
https://ridewithgps.com/routes/39048470

I will be on a road bike (with panniers) and am looking to stay on roads or cycle paths made of concrete and not dirt. I've used google streetview on quite a bit of the route and where it appears to be on main roads, sometimes there is a cycle path running alongside I can use.

But grateful for any advice from anyone who knows the route

Thanks