Tomcat 8 uses /var/tmp/<name of tomcat instance> as the default location of CATALINA_TMPDIR. It fails to start if that folder does not exists already.
Since my /tmp and /var/tmp are both tmpfs, it is cleared on reboot. This means the CATALINA_TMPDIR is removed on reboot (as it should). This prevents Tomcat from starting automatically.
But since /var/tmp is world writeable, the startup script could create the CATALINA_TMPDIR itself. Can you modify the default start script, so that it tries to create the CATALINA_TMPDIR before failing?