Does one 'low' pressure system feed another during the winter?
Yes...one low can 'feed' another! A moderately close look at a weather map or satellite image will often show several lows close to each other. They may rotate or circle around a common point, like two skaters linked together on ice...or one may rotate around a stronger low...like the planets rotate around the moon. It's all a consequence of physics. One of the lows may 'steal' energy or moisture from another low...allowing it to intensify while the other weakens.