“First ice” and “last ice” are just terms that “usually” coincide with the calendar. Don’t fish the calendar, fish the weather conditions.
If your lakes are just starting to form safe ice in mid January, that’s your first ice. If it all melts in 2 weeks, that’s your last ice. If it refreezes into fishable ice again, you get another first ice. Fish use the weather as a trigger to know when and where to go in any given body of water. Including spawning. Of course, every body of water is different and lake composition/weeds have a lot to do with it too.
Just like when trees start budding in February because it’s 65 degrees, fish follow the same trends.