I was there last year on Black Friday. It was cool getting out (55 and Sunny), not cold. This time of year, the weather is highly variable. On the way home, it snowed.
Due to the depth, you can dive easy for 90+ minutes on a single tank. 3MM is fine and preferable due to the shallow depth. FYI: We saw a total of 4 other divers all day.
Last year, the only local restaurant was closed on Black Friday. Had to drive a bit to find food. Bring your own (at least lunch). The dive shop down the road was open for fills, but the owner tends to hang out at a building next door so you have to hunt him up.