I've moved a partition in my house, widening a short (4' long) section of hallway by about 7". The hall is floored with standard red oak strip flooring, running across it rather than with the length of the hall. Moving the partition has exposed a bit of subfloor (about 4' by 7"), so I need to patch the hardwood. On the side of the hall opposite the patch area, the wood strips run through a doorway and under a small section of wall-to-wall carpeting at the base of a stair. So, would it be better to...

1) tear up the existing red oak in that section of hall and replace it with new, all the way across the hall, necessitating that I take up the carpet at the bottom of the stair and put it back down afterwards, or...

2) Cut back the strips at random lengths adjacent to the patch area and "weave in" a minimal amount of new flooring?

Extra credit: if weaving-in a minimal patch is the way to go, what's the best way to cut across an installed strip of flooring without damaging adjacent pieces? A router and a small straight plunge bit, maybe, with a chisel to clean out the corners? I do a lot of woodwork but you flooring guys must have some tricks I'm not thinking of.

Thanks for any insights.