My favorite squash is ButterBush. Small vines and you do not need to worry about lost space. Also just the right size for single servings (I live by myelf). They also keep very well if properly cured. The last one I cut up had been harvested almost 18 months earlier and was still in edible condition.

For full sized squash vines try some short seasoned interplantings like lettuce, daikons, baby carrots, early bok choy, napa, turnips etc. or split the row with a row of short vined green peas. Or run a row or two of taller marigolds right down the middle. You might also try a row of middle sized sunflowers. Even if not for seed, the flowers do very well in a vase and the stalks will stick up over the squash vines better than peppers or maybe even tomatoes. IOW interplant with something you can enjoy looking at or eat right there on the spot. Daikons and turnips are too often overlooked and so is spring napa. A lot of those you can "square foot" between the squash rows you plan so far apart and have them harvested and out before the squash vines really start to run.