Also, another serious problem with any of these ideas is that Spacey (along with Wright) are both executive producers. He'd surely have to agree with being written out and the show continuing without him, and then you'd have the contentious issue of someone who's become embroiled in accusations of sexual harassment en masse continuing to gain financially from the show. I don't see any way it can continue. Either recast Frank or release the scripts online...I don't know if there's any precedent for that but I'll be damned if I don't find out how this was meant to end.
tbh, I don't know what's worse, the inevitable 'Frank gets killed' ending anyway which I think is beyond lazy, him being killed off-screen, or the show not continuing at all