Looks like Colchester will be clear of snow in the next few days (according to the BBC website): -
Tues 21st : 12pm Light Slow, 3pm Sleet, 6pm light rain, 9pm & 12am Heavy Rain <- All during temperatures above Zero degrees.
Wednesday onwards <- Clear weather.
Checked Devon, Exeter (Not sure where in Devon you are travelling to Gaz), but no snow for the next 7 days.