I need to water my plants daily with a gallon or so of water per plant at the mid and end of flowering. If I didn't water, after 4 days I would have multiple dead/wilted plants. I grow mine indoors in
Promix, but they get pretty big compared to most tent grows. I would get a basin under the plants to catch any runoff, just to see how much water the plants use in a day. Sitting for 4 days with standing water won't hurt things, but I wouldn't go any longer than that without a dry period. I know it isn't good to have roots in standing water, but a few days won't hurt and I have done it many times. If you have a few days warning, try experimenting and see how they respond to not getting watered regularly. Everyone's setup is different and what works for me might not work for you, and vice versa. Good Luck!!