The remainder of the 2020 Guinness Six Nations will be accommodated in the last two weeks of October, according to a temporary international calendar proposal by World Rugby's executive committee.
It follows Six Nations organisers declining to comment on remarks from French Rugby Federation president Bernard Laporte in which he claimed that Ireland and France will play their postponed match on 31 October.
Ireland also have an outstanding fixture against Italy.
The first two weeks of the proposed 24 October to 5 December window would include the remaining fixtures of the men's and women's Six Nations tournaments which had been postponed due to the Covid-19 pandemic.
A rest weekend would then follow on 7 November, before the window concludes with a period set aside for fixtures between Six Nations teams and other international sides which will be hosted in the northern hemisphere from 14 November to 5 December.
Fiji, Japan and Georgia have been tipped to be among two national sides under consideration to join Ireland, Scotland, Wales, England, France and Italy for a mini-tournament of eight teams during that period, which would conclude with a 5 December final, following a pool stage.
Wales will not play at the Principality Stadium again in 2020 with the stadium set to remain as a field hospital.
The ground has been converted into the temporary Dragon's Heart Hospital and is set to continue as a medical facility in case of a second coronavirus spike.
The Welsh Rugby Union is in negotiations with the Welsh Government and Cardiff and Vale University Health Board to keep the temporary hospital in place until autumn, and then have the stadium back as a rugby venue for the 2021 Six Nations.
Wales were due to be playing their rearranged Six Nations match against Scotland in Cardiff on 31 October.
World Rugby has also proposed that the 2020 Rugby Championship between leading southern hemisphere nations will run between 7 November and 12 December and also be hosted in a single country.
"The rescheduling of the domestic, European and international calendars will accommodate the ability for the professional clubs to have access to their star southern hemisphere international players for the completion of the postponed and rescheduled 2019/20 seasons at a time in which they would have ordinarily been on international duty in August and September," World Rugby added.