At the risk of sounding cocky--and later having to eat my own words--I am happy to announce that Presley is now consistently sleeping 7-8 hour stretches at night! She has even gone as long as 9 hours without a feeding. At six weeks old, this is quite an accomplishment. The downside, however, is that she tends to start her 7-8 hours at around 9:00 p.m., meaning that she's still ready to eat by around 4:30 a.m., much earlier than I would desire. And it doesn't really seem to matter when I feed her at night--she still thinks 4:30 should be breakfast time.
Regardless, I'm still getting a decent amount of sleep, and for that I am very grateful.