The Six Nations could be played as a home-and-away tournament next season if the coronavirus pandemic prevents the autumn internationals going ahead as planned.
RFU chief executive Bill Sweeney remains optimistic it will still be possible for England to play planned Tests against New Zealand, Tonga, Australia and Argentina in November, but said several contingency plans were under discussion, including an expansion of the Six Nations to fill the void.
"The preference from both the north and the south is that the original programme will go ahead," Sweeney said. "But of course that's driven a lot by international travel restrictions so both (the north and south) are developing back-up contingency plans.
"There are two or three different options we could go ahead with that feature more northern hemisphere competition around that autumn window.
"One of them if you'd play a Six Nations tournament in that autumn that would combine with fixtures next year and for the first time ever you'd have home and away. It's possible. Every (plan) has pros and cons to it and those are being evaluated."
Plans are already in place for the remaining fixtures of the 2020 Six Nations, suspended amid the pandemic, to be played later this year.
Sweeney said it was too soon to say with any certainty whether international rugby would return behind closed doors, with the RFU looking at several possibilities, including looking at how Twickenham could host games with social distancing in place.
"You would be surprised the impact (a two-metre social distancing) rule has in an 82,000 seater stadium but one metre has a very different impact," he said. "We've run every model so we've got a sense of what that does."
The RFU on Tuesday announced roadmaps for the game to return at the community level as lockdown restrictions continue to ease, though the situation remains too uncertain for a firm timetable to be put in place.
Sweeney called the community game the RFU's "lifeblood" but said the organisation could come out of the crisis strongly.
The RFU had been looking to pay off remaining debts following the redevelopment of Twickenham's East Stand by 2022 but that will be now be delayed.
"This is not a 12-month bump in the road," Sweeney said. "This is much longer-term fix. The consequences and impact will be with us for some time.
"We were investing in and will continue to invest in our high-performance pathways...We've got an outstanding crop of players and a World Cup coming up in 2023. We've got a great head coach and we want to make sure we don't go backwards in any way.
"We're making good progress in the women's game and we need to be sure that remains a key focus for us and make sure the women's game is not impacted disproportionately."
It was announced last month that Tyrrells will end its sponsorship of the Premier 15s in August, but despite the economic downturn caused by the pandemic, Sweeney said potential partners had already expressed interest in backing the women's top flight.
"Some companies are in better shape than others and some see a very good opportunity to enter a market that's maybe a bit distressed," he said. "That's why we wanted to get the announcement out there.
"We have got a couple of very serious, significant players who want to get involved in women's sport and possibly in women's rugby, so we're optimistic we can make something happen."