We went through this last year. It wasn't my favourite time to commute. I fear this year will be worse I normally board at Clayton, but for last years shut down, I drove myself to Westall and parked there to get the express buses.
The first week was actually pretty good. Very few people, and out of 10 trips to/from Westall, 8 of them were in decent coaches, 1 was in a school bus, and the other in an old bomb of a bus brought in from who-knows-where. Most days I had two seats to myself, and got free largesse courtesy of Metro (drinks, donuts, icy poles etc). My trip to/from work in fact became substantially quicker than the train.
The second week wasn't so good. More people returning work meant busier services and frustrated passengers who clearly live in a bubble and weren't expecting buses, particularly on the Monday. The free stuff dropped off, and the quality of vehicles also decreased. I ended up with my knees around my ears a few times.
By the third week I gave up and drove to Mt Waverley. Unfortunately, I wasn't the only genius with that idea and had to park a substantial distance away even at 7am (15 min plus walk) I only lasted a few days before I gave up. I ended up working from home for the remainder of the time.
The only bright side was that the bus replacements were free travel. Well, I tell a slight lie. Passengers were meant to tap on and off and pay for their journeys. I just never did. The one time I was challenged about it at Westall I said "Oh yes I'll tap on at the platform" then crossed the bridge walked to my car and drove home. #winning