20' X 4' sounds like a hallway. Do you mean that there is 4' wall-to-wall, or from the counter front to the opposite wall? It's difficult to imagine that anyone would build a kitchen with a 4' dimension from wall-to-wall. Standard base cabinets are 24" deep. That would leave less then 2 feet of working space. Can you verify or clarify the dimensions you've given? 4 feet wall-to-wall sounds too improbable.

It does sound imporbable.

However, there are a couple of ovens (no t cooktops, just ovens) that have french doors, which halve the depth requirement, but I don't know if any of them are electric. Can you get propane or natural gas?

i also believe that there are a couple of ovens made with side opening doors that take less walkway depth.

And please post of drawing of your kitchen here or in the Kitchen Forum. Lots of creative, experienced around there.