How long will a casserole keep in the freezer?

I made some lentils with sausage and greens in February of last year. The excess went into the garage freezer in a large plastic container and has sat there ever since. The freezer is kept at a high setting and is opened very infrequently.
Question is whether the casserole is still going to be good to eat.

I understand that the only way to find out is to actually defrost it and eat it but I don’t want to find myself at dinnertime looking for something else to cook or eat. I want an idea whether I can count on this still being OK to eat.

SRM