If there is any attic space at all or you get lucky with the joist bays you will likely be able to fish a.
Run wire above ceiling joist no attic.
In addition your light fixture may require mounting to a ceiling joist or to two short blocks nailed.
For vertical work you can cut about 6 inches below the wall ceiling joint drill through the top plat and then fish from the opening ion the ceiling.
Worst can you open the ceiling 5 inches from the wall and work from there.
The access is 14 because it s constrained by the 16 centers of the ceiling joists.
If there is access above the light in an attic or kneewall space you can remove the wire from the existing fixture box and install it in a junction box.
You can then splice on a new piece of wire make sure it is the same wire gauge and run the new piece from the junction box back to the fixture box.
A 3 inch strip of drywall is enough to run receptacles around a room.
In some cases you can run the electric wire beneath the ceiling joists.
The actual install of recessed lights here https youtu be 5yc8aqnvqqg the long bit is actually used.
If the wires are within 7 of the attic access hole or along any attic flooring you ll need.