In March of 1917* when Wilson was inaugurated for his second term, the US was not yet involved in WWI. We didn't enter into the war until a month later. He was inaugurated and there was a parade but no inaugural balls according to this source.

"In 1917 -- with President Woodrow Wilson -- we were on the eve of World War I, and it was a very solemn inauguration," Bendat said. "There was a parade, but there were no inaugural balls."

Here's his second inauguration speech.

As for FDR's 4th inauguration, the man was extremely sick and near death. He died less than 3 months later. Look at some of the pictures of him from that time and you'll see how bad his health was, such as this one from the Yalta conference in Feburary, 1945.

*Presidential inaugurations used to take place on March 4th. They decided that was too long after the election, so in 1933, the date was changed to January 20th as part of the 20th Amendment. FDR was the last president to be inaugurated in March (in 1933) and the first to be inaugurated in January (in 1937).