My husband had a quilt like this that his grandmother made for him when he was in high school...he asked me to repair it before we were married. It was all polyester double knit with two wool blankets inside instead of batting. None of the squares were the same size and because she had hand sewn everything and simply "fit it in" nothing matched up. It was horrible, but he loved it.
She had used yarn to tie it instead of quilting it. I bought yarn in the same shade and retied the whole thing. We haven't used it, but it remains in the linen closet for some night when the power goes out during a winter storm.
Tie it and be grateful we don't do this type of projects anymore. You can do it!