I have just done a very long stint on fox & badger with a .25-06, probably the biggest calibre I'd want to use for fox (loud too, think about night time), but it will also take the big stags every time too.
For a dedicated deer rifle on the hill, if you forget about foxing for now, then a .270.
For a dedicated deer rifle on the hill, if you forget about foxing for now, then a .270.