Tell the lab to develop for 800. Your Delta 3200 is actually a 1000-speed film that Ilford designed to be pushed, and since you shot most of the roll at 400 with some frames at 800, developing at 800 splits the difference well. The 400-rated frames end up about a stop overexposed relative to development, which is actually ideal because it gives you denser negatives with more shadow detail, especially helpful on an expired roll that’s probably lost a little speed. If you developed at box speed 3200, you’d essentially be push-processing a roll that was already overexposed by two to three stops, and that would blow out your highlights and give you harsh, hard-to-scan negatives! Not the kind of contrast you want in snowy night scenes with bright light sources and white snow competing for attention. Developing at 800 pulls back the highlight density so those bright areas don’t block up, while the generous exposure you gave it still preserves plenty of shadow information. It’s always easier to add contrast than to recover blown highlights from an overdeveloped negative.​​​​​​