Reay also wrote articles as a war correspondent for The Herald and the South Australian Register until he returned ill after the capture of Bloemfontein.
He retired from the Mounted Rifles in 1903 with the rank of lieutenant-colonel, although, perhaps with an eye towards the likelihood of further hostilities, he wrote a report on the training of volunteers based on the Swiss system.
For this work he was appointed Officer of the Order of the British Empire (OBE) in 1917 and promoted to Commander (CBE) in the 1920 civilian war honours.
Reay married Lucinda Braithwaite Broadbent on 10 April 1882 at Hotham Hill, Melbourne, and had five daughters, two of whom were nurses; one was awarded the Royal Red Cross and the other worked for the hospital voluntary service.
Reay died at the Memorial Hospital, Woolwich, London, a day after his 71st birthday, and was cremated at West Norwood Cemetery, where his remains were scattered.