question is why you need to
I would think the real issue is why should you need to adjust the offset for zero? If it is purely mechanical (mounts moving, effect of temperature on the gun or scope geometry, etc) then it shouldn't matter very much for other distances. With the current low temperatures the air is 'thicker' so the trajectories are affected across the range and that will mean new aim points regardless of hold-over or elevation clicks. Then there is humidity and altitude, effect on regulator (fps), etc, etc.
Odds are the temperature will change over the duration of the course so it will come down to the usual "hmm try this one with a few more clicks or give it a few more yards holdover".
All adds to the fun of target shooting outdoors in the UK weather :-)