Appear offline but still play

Is there really not a way to appear offline but still play. Bush League Riot! This is a function people want sometimes. I use it on my Xbox all the time for COD. I just want to get in a few games by myself because I don't have a lot of time. Also I don't want to slight people by rejecting invites making them less likely to want to play together in the future. FYI The last few weeks I have stopped playing League when I'm time crunched solely because of this function. Instead I bought Raft and the Forest on steam. Good games!!