I hope people in dioceses with a problem (vast understatement) do redirect donations, then when they have the big Bishop's Conference in June, Loverde, Bruskewitz & Chaput can say "Gee, people aren't supporting YOU? WE don't seem to have a problem."
If "Copper Sunday" is just done across the board, in every parish in every diocese regardless of priest or bishop activity, that looks more like a lack of support for the Church in general than a lack of support for a particular Millstone-award candidate.
You could then direct your offering to a ministry in your parish or simply deliver your Sunday offering to the parish office during the week and still place the penny with a note in the collection basket.