Public health expert Professor Linda Bauld warns the rules are "complicated" and people will interpret them as they see fit.
The Edinburgh University public health expert tells BBC Radio Scotland's Drivetime: "So if it’s three households, does it matter if it is four?
"And then the travel is potentially more concerning to me as people will be travelling from a high to low prevalence area and vice versa.
"We’ve seen in other countries that opened up slightly for festival periods you do see cases go up afterwards and we need to be ready for that."
Prof Bauld said people may inadvertently put older and more vulnerable relatives at risk.
Quote Message: If people really throw caution to the wind then we need to be prepared for more cases in January and that may mean that some of the areas that have lower restrictions might have higher restrictions in January. from Prof Linda Bauld Public health expert at the University of Edinburgh