FYI repairing holes in woolens is not very difficult at all, even large holes. It is about as time consuming as knitting a new section that is a little bigger than size as the hole plus a bit more for anchoring (or in other words, it is way less work then knitting a new piece, a 1 inch diameter hole would take less than 10 minutes to darn with one wool color).
Sewn leather patching over worn holes with old woolens is also very common too, particularly on high wear areas like elbows and knees.