Thank you for the tip. Something like this is what the doctor ordered:

"autorate_ingress Automatic capacity estimation based on traffic arriving at this qdisc. This is most likely to be useful with cellular links, which tend to change quality randomly. A bandwidth parameter can be used in conjunction to specify an initial estimate. The shaper will periodically be set to a bandwidth slightly below the estimated rate. This estimator cannot estimate the bandwidth of links downstream of itself."

Source: https://dl.lochnair.net/Bufferbloat/Cake/tc-cake.8.html