Great stuff everyone - thanks! Sounds like my best bet is to warm up the keg for a couple weeks and see where that lands me. It's already partially carbonated in the keg, can the diacetyl be cleaned up in a pressurized vessel, or should I vent the lid (maybe leaving it open) for part of the cleanup period? Also, since most of the yeast has been removed (though it's still somewhat hazy)would adding another sachet be beneficial? It's sitting at 1.007 and ~7% ABV.
FWIW, I was very gentle and slow in removing the hop bag (from fear of oxidation), but also did not want to leave hops in the beer another week and risk extraction of undesirable 'green-ness'. I am new to the 'dry hop during fermentation', but sounds like I should have just left them in and changed my racking schedule if I was concerned over-extraction.