mik3bravo
The answer to your question is that an extension to runway 23 (it changed recently from 24 due to magnetic variation over time) is not technically feasible.
SEN is classified as a Code 3C aerodrome due to its runway width of 36m and as such is subject to a maximum declared TODA of 1799m. The runway is in fact 1856m in length and it would be necessary to widen the runway to 45m in order to declare the use of even that extra bit of pavement. That's where the problem lies as Eastwoodbury church would then come within the runway strip width so the full existing 1856m couldn't be declared usable let alone any further extension.
I used the word 'feasible' earlier because it would be theoretically possible to move the church and overcome the other obstacle problems that a widened runway would encounter. Any extension to the south-west would likely be extremely limited as a 240m RESA would still have to be provided; this currently being the land between the end of the starter extension and Nestuda Way.
All definitely a non-starter I would say.