I was told that 501 squadron will be active until the end of this financial year which is March 2020 and 301 squadron would soldier on until March 2021 - however I haven’t seen any official confirmation of this and it doesn’t mean that the RF-4s will actually be flying in January 2020. They may fly as per usual or they may wind down operations. I don’t have my notes handy but I think we only saw 7 operational RF-4s and as planes come to the end of their hours (or need repairs) that this number may dwindle,
No one can predict if you are going to see Phantoms fly but in your place I would plan to spend a few days along the fence.