Temperature was 29 degrees when we had no power for two days and no water for 3 days. When power and water was turned back on, the bathroom flushed OK for about 3 times. Then it stopped filling with water and will not flush. The bathroom sink has water coming in right next to the toilet. Could maybe a pipe have burst or maybe frozen in those few days?

Try turn off valve then remove the water line from the toilet tank check that water flows,
If water flows check toilet hardware.