Somewhere round the godawful Beaulieu development would be feasible i suspect, new train station, relatively cost effect land assuming the CG sold for housing, and a notional population on the doorstep. I say notional as i suspect its a desert in the day time and would provide the number of fans you could count on one hand for most games.
It would be a disaster for attendances i think, however; train travel is horrendously over priced, the despite the ramshackle appearance, our town centre location is a huge plus. We are one of the few grounds slap bang in the middle of a town, taunton is too, worcester to a lesser extent, and it must help our attendances no end. in both 4 days cricket and t20 with boozed up off the the train commuters (before anyone takes objection to that, i have been that soldier) who can the continue there evening out easily after (which they couldnt despite the station at Beaulieu. I think moving would be pointless, we may have a nicer looking more modern ground, but we wont get international cricket and we won't maintain the current attendances.
We could easily spruce the ground up if we so wished.