Leaders of Cockfosters and North Southgate Synagogue are consulting members over a redevelopment plan for one of the United Synagogue's most geographically spread-out areas.
A strategic report calls for a "completely new premises model" for the future with a community centre and a network of local minyanim which could also accommodate members of Palmers Green and Southgate Synagogue.
The plan envisages a single congregation, Kehillat Shaarei Darom (Gates of the South) "spread across a number of centres with shared services".
Cockfosters chairman Maurice Diamond said: "A lot of communities which have been around for a while have not renewed themselves. We want to renew ourselves."
But he stressed: "I am very keen that the strategy is owned by the members and is something they want to do, not something imposed on them."
Although the synagogue's main base is in Old Farm Avenue in Southgate, it already operates satellite minyans in Hadley Wood and Cockfosters. The plan notes a need for a fourth minyan in Southgate Green, which could conceivably serve Palmers Green.
The team that drew up the strategic report - including a representative from Palmers Green - believe "the most sensible option" is for Palmers Green to close its building in Brownlow Road "within a short time period" and put its assets towards the KSD community.
"Many communities have separate minyanim on the same site, for example Finchley," the report said. "We would just locate them to different sites."
The Old Farm Avenue site could be redeveloped to better equip it for youth and community activities. But the building was old and had "started to leak", Mr Diamond said.
"It's got a lot going on there. We have the Cockfosters Learning Centre on Monday nights and there are over 70 activities a week. We want to retain the centre while having small minyan halls that will bring more people in. We know we have a lot of members who live on Southgate Green, so it makes sense to set up a minyan there."
An alternative scenario would be to make the Wolfson Hillel Primary School the main "community hub" for the area. In addition, the remodelled community could share administration with Barnet Synagogue to cut costs.
Cockfosters had nearly 1,500 members in 2010, but male membership has declined by over 40 per cent in 25 years from 1,121 to 664, while women's membership has risen from 300 to 830. It has far fewer members in the 21-50 age group than the United Synagogue average and far more in the 60-plus category. Palmers Green has an even older age profile.
The report warned that if no action was taken, "they will naturally collapse as communities", in the manner of Kingsbury and Dollis Hill.
Mr Diamond said the aim was to complete the redevelopment by the end of the decade. "We are not trying to extend ourselves. And we want to make sure that members feel comfortable with it."