A little late for OP but for everyone having the same issue:
The internal style sheet used by dash has both min-width
and max-width
set to 300px
. If you want to resize the tooltip, you likely have to unset one or both of them.
As an example: the following CSS rules will yield an adaptive-width tooltip with maximum width of 300px
.dash-table-tooltip {
width: fit-content;
/* max and min width are both set to 300px in the dash stylesheet. Override them with your own definitions. */
max-width: 300px;
min-width: unset;
}