Hitler had a meeting with Blomberg and Fritsch in november 5 1937 to plan the invasion of Czechoslovakia, but they were against it so he replaced Blomberg with himself and Fritsch with Brauchitsch. Still most of the generals was against the war because they figured Germany was not ready.
September 14 the Leader of Abwher, Wilhelm Canaris, made Task Force Z with order to arrest Hitler for war mongering. He got support from Franz Halder, Beck, von Weizsacker, Goerdeler, von Witzleben, von Helldorf, Nebe and a lot of other generals.
The man who saved Hitler from jail, was Chamberlain that suddenly showed up in Germany with his “Peace in our Time- BS” and told Hitler he could have Czechoslovakia. If Chamberlain had stayed home, then Hitler would have been arrested again, and went to Landsberger Prison for a second time, and there would not be any attack on Czechoslovakia.
But for the fun of discussion, lets pretend Hitler did attack.
At that time, 51 % of the population was Czechs, 23 % was Germans, 15 % Slovaks, 6 % Hungarians, 4 % Ukrainians and 2 % Polish.
At the election in 1935, 16 % voted on the Czech Nazy Party with Konrad Henlein as Fhurer.
Based on this facts, I figure that an German attack against strong mountain positions would soon have been bugged down into a stalemate. Germany would run out of fuel, and soon be overrun by French and Russian troops in a doubble pincer move. The minor states like Poland, Hungary, Romania etc would never join Germany since that would be suicide. They would rather join Russia.
So Germany would again be occupied, propably early 1939, and Czechoslovakia would be likely to see a Civil War between the different ethnic groups, just like Yugoslavia did, but Russia would most likely make peace in all Eastern Europe like they did from 1945 to 1990.