In March 2018 I've ordered a Cat 1-5 Cert to get 35% more Avios. My plan was to use it for a Stay in Dec 2019 which I could book in Jan 2019. The Hotel is now cat 4 so no problem. Now I read about possible cancelations of these Certs in August 2018. Is a date change with this certs possible ? Such as I book now the Hotel for May 2019 and in Jan 2019 I will change it to Dec 2019..
Cheers