Great location and the flat is well equipped if you stay longer (we stayed 2 nights). There are plenty options close by in Stockbridge for dining at any time of the day. Also small supermarkets and lots of independent grocers/cheese/butchers/wine merchants and the lovely Stockbridge market on Sundays if you’re doing some self catering.
Once you’ve exhausted the delights of Stockbridge it’s only a short walk (or quick bus ride) to Princes Street etc. If you want to stay away from the busier areas then a walk along the Water of Leith is a great option.