Neutral density filtration between the light source and the negative. I don't know if your enlarger allows for that. But large ND sheets are terribly inexpensive if it does. This has worked well for me in the past.
I cut out a set of 1-, 2-, and 3-stop custom filters. In various combinations they allowed me to stay near or right at my preferred enlarging lens aperture, while still giving me my preferred exposure time length for comfortable dodging and burning.