I keep thinking I should freeze stuff...but I have limited refrigerator setup at the moment...Stick it in the freezer. I regularly make several portions of meals like that and freeze the surplus.
I remember not liking spaghetti as leftovers when I was young. I think it was something about the seasoning packages my mother used. When I started cooking--such as it was--I'd make pasta sauce from scratch, and that seemed to work well as leftovers.

