Depends on the Protestants. Anglicans definitely do, Lutherans do, some Methodists do, some Presbyterians do in some form or another. Basically the further you get from Catholicism, the less likely they’ll celebrate Lent in the way Catholics do. Baptists, Mennonites and other Anabaptists being the main exceptions who don’t celebrate Lent or really anything associated with the season in any form.
I can speak from personal experience that Anglicans definitely do celebrate Lent. Got my ashes at 7:30 this morning before work. And while the fasting and abstinence rules are a bit different than the RCC, they can be comparable if one so chooses. They were definitely comparable in the old 1928 Book of Common Prayer and the 1979 BCP allows for that to continue if the congregant so chooses.