Well, this morning the problem was the crazy low tide!
I couldn't budge the boat closer to the dock to let the pup dog ashore. I figured we were aground. But no, the stern lines were just way, way too tight due to the low tide. I definitely should have gone out in the night to loosen them up... And because they were so tight and with incredible load, I couldn't get the cleat hitch undone on either stern line...well, the initial hitch was no problem, but where the line wrapped around the cleat it was "trapped" in place by the tension of the line running to the piling.
I was beginning to think I'd either have to wait for the tide to come in or cut the lines... and believe me, between both the expense of these fancy New England Ropes dock lines and the emotional investment in them from having spliced them with the floppy-haired sailor guy, I was loathe to consider cutting them unless they were going to sink the boat. So I sat there wiggling them and waiting for any millimeter of slack caused by a wind gust, and eventually managed to tease them free. Once I had loosened the starboard stern line I was able to pull the boat over to the dock (I have now looped a spare line around the dock piling just for this purpose). Pup dog still looked askance at me asking her to jump up so high to that narrow finger pier, but her need to piddle eventually outweighed her hesitation. Getting her to reverse the process and make that long jump down onto the narrow side deck...not happening. So she's leashed to an Adirondack chair ashore, braving the cold wind and, hopefully, enjoying the sunny day to watch the ducks.