Hi Hedy!
I've so far not been able to find much more information. On George's border crossing record, when he went to Wyoming to see is sister Anna, it gives his arrival in Canada as 1924 aboard the Andania. So I looked that up and found his record of landing, which I'm attaching. The ship sailed from either Hamburg or Cherbourg, sailed to England and departed from Southampton for Quebec on 1 August 1924. That is much later that you thought but also explains why I couldn't find any earlier records of George in Canada.
There are a couple of interesting things about the record of landing. First, his name is Jiri on the passenger record so he probably chose George as the closest English sounding name. It says he was born in Baremince, Czechoslovakia, at least that's how the person taking his information spelled it. I'm trying to figure out where that might be. He says he had been living in Orlava which would be Orlová, Czechoslovakia. There is another passenger with him named Andraj Levkulich who is also from Orlová and appears to be a cousin. They both gave their final destinations as Winnepeg, Manitoba. I haven't been able to find anything more about Andraj.
George is listed as married and gives his wife's name as Ialene Levkulich. It was quite common for the husband to emigrate first, find a place to live and get established and then send for the wife and any children. I'll look and see if I can find anything about Ialene but so far it doesn't look like she ever made it to Canada. When George went to see Anna in Wyoming (1927), he listed himself as single. So maybe Ialene died. When he went to Alaska in 1936 his still listed himself as single. When he went in 1947 he listed himself as married. So he married Mary Simasz sometime between 1936 and 1947.
So far I haven't been able to find a passenger record for John or Anna but I'm still working on that.
Now that we have a definite place - Orlová - I can see if there are any vital records or censuses for the area. Will keep you posted.
Best to all the family,
Soosi