A flowline system for transferring cryogenic liquids between a cryogenic liquid storage tank and a cryogenic liquid receiving/loading facility, and a method of maintaining the system at or marginally above cryogenic temperature during periods between transfer of cryogenic liquids between the cryogenic liquid storage tank and the cryogenic liquid receiving/loading facility are provided. The flowline system has a main transfer conduit and a vapour return line in fluid communication with the cryogenic liquid storage tank and the cryogenic liquid receiving/loading facility. A cooling medium line is provided that is in fluid communication with the main transfer conduit, the vapour return line, and a source of cooled boil-off gas, wherein the cooled boil-off gas is at or marginally above cryogenic temperature. The cooled boil-off gas is circulated between said tank and said facility through the main transfer conduit and the vapour return line during periods between transfer of cryogenic liquids to maintain the main transfer conduit and the vapour return line at or marginally above cryogenic temperature.