It will go on indefinitely IMO or until Trump is brought down. The swamp uniparty, including Ryan and McConnell are more than supportive, if not conspirators themselves, in bringing down the Administration.
There is no doubt that the endpoint is Trump’s removal from office.
Ryan (Romney) needs 25 GOP “yes” votes to bring charges to the Senate. Does anyone doubt that their are 19 GOP Senators who would vote to remove Trump today? There are probably thirty!
Mueller’s job is to create a fig leaf for the 25 votes needed in the House. That’s his mission. That’s why, by the way, he’s been practically begging to be fired.
Ryan, Romney, McConnell and Bush know Trump is thin-skinned and might lash out if provoked. Ryan probably has his speech declaring for impeachment already written - heck, it’s been written for him, for months.