The broken pipes, fittings are one thing. Relatively 'inexpensive' to replace, but maybe a pain to get at.
A bigger problem, if break and leaks are not discovered right away. Think ice melting in the spring, but you don't open/dewinterize for another month or two. That water now has now been absorbed into carpet, wood or other porous material and beginning to mold and mildew. That would make a would make replacing a fitting look easy. Even better, properly winterize.
To see how much water expands when frozen, simply fill an ice cube tray perfectly level with the top, put in your freezer for a day and then see how much above the level that you filled it to.
The ice cube tray did not break because it expands into the open space.
Ken