Another method is using a spray bottle for bathing, ideally filling the bottle with fresh water daily, and using a mister likewise, a more gentler sprayer which mimics morning dew and adds humidity
Tulasi doesn’t require much water in winter. Only if her pot feels light and soil dry, give her a good soaking until the water runs freely from top to bottom of the pot. And if you have hard well water like we do, occasionally a little sprinkling of Epsom salts on top of her soil, helps her take up nutrients better. Epsom salts diluted in water in a spray bottle also helps for her to absorb directly through her leaves. But do not do this everyday.
Keep her on a sunny window ledge during the day and remove her in the evenings, so she doesn’t catch a chill.
Caring for tulasi helps us build a relationship with her and pleases Lord Krishna very much.