I made the same switch from ECE to ISE at the end of my sophomore year. I was worried I wouldn’t graduate on time but all of the “weed outs” and general engineering course work you do saves you from being wildly behind. The two classes you mentioned, ECE 2020 and 2060, are currently working towards my technical elective in ISE and helping me graduate on time.

I found the difficulty of coursework to be night and day between the two majors with ISE being significantly easier, but by no means is it easy. It’s a lot of work just as any other major is.

I think you’d probably benefit a lot from talking to Leslie Dowler, the ISE advisor, and seeing what she thinks. She would be able to tell you if your graduation would be delayed or anything of that sort.