This pattern won't work for all names. If the last name is Oz then it is not going to look correct. Maybe you could use "Oz Family". You should be able to get nine letters on the sign without changing the size of the letters.
Don't forget that you can use the Poster Print feature of Adobe Acrobat Reader to print the pattern larger. In the example below I set the poster to 150% and the pattern is around 14" wide printed on four sheets.