I understand what you're saying, I thought I should point out that not everyone finds it a bad experience. We were warned about temperatures, noise, being jolted awake, lack of restaurant car etc but found it was brilliant. Maybe if you go expecting the worst then the reality is better!
I would always pay the extra for a private cabin (T2 ... there a two types, "upper" and "lower", we preferred the "upper"). There is a washbasin in the cabin, but the toilet is at the end of the corridor. On our train there was breakfast served in the restaurant car. I can't tell you how magnificent it was to see the mountain streams of the Alps as we emerged from the tunnel at 7am in the morning!
We used Railsavers for the motorbike trip; I don't know if Alison is still with the company but she is a biker and was able to give us loads of relevant tips.
It's difficult to say what my wife does...
She sells seashells on the seashore.