Yeah I was the same! Here I was looking forward to these train trips in Europe and then with COVID, travel restrictions etc - I thought I would take a look at what I could find out of BNE.
Clicked around in here -
Queensland Rail Travel Home
The Westlander that I went on has had its services cut over the years so it doesn't have a sleeper. The seats were large and with social distancing I don't think you would have someone next to you in any case. The seats recline, there was a shower in the front of each of the two passenger cars and a basic dining car. It was basic but it was a nice area. I was happy in the morning to just sit and watch the countryside go past.
Service was excellent - there were more staff than passengers on the first hop up to Toowoomba. I didn't research too much and was surprised to get food. It isn't much (sandwich, fruit, cake, juice and cereal for breakfast) but it was fine. Bar options were limited but they had beer and wine so again - I was fine.
I had a train spotter, if that is the right word, on the train and he filled me in on everything! The train to Longreach sounds great. Multiple cars with restaurants, bars and if you go 1st class you get a private cabin with a seat and a bed. I am planning a trip to Longreach later this year and I am thinking one leg might be via train now. He also recommended some 2 for 1 deals they have at the end of the year. Only problem is it is pretty hot by then.
From what I understand the Westlander train is rarely busy. That is just what I was told though.
As for sleep - I managed to get a solid 5 hours uninterrupted from Toowoomba to Roma. I don't think the train stopped once in that period. If it did - I didn't wake up.