What if instead of having a Flexcap, there is a FlexMinFee with headroom?

[Joseph Woolfridge]

One of the ideas i've seen in the past is for a flexible blocksize cap to handle transaction surges (because demand is not always constant) . If miners could enforce a minimum fee and this minimum fee flexed so that it surged, then it would maximize miner revenue, prevent tragedy of the commons, and make life easier since the "max blocksize" wouldn't have to be constantly adjusted? I'm not sure how the enforcement of a minimum fee flexible or not would work. Maybe slightly increase the purposeful orphaning risk for each infraction?