Apple used to say don't do it.. for some reason they deleted that part of the original icloud BTMM instructions.. I think you will find TM simply won't work.. but if you do setup iCloud and BTMM to get access to the TM backups.. let me encourage you.. DON'T DO IT!!
TM doesn't just backup.. it runs indexing and checks the backup.. it is highly interactive with its backup doing scans and comparing files.. What will happen.. and this is 100% certain.. is one day some part of the internet will drop out half way through the backup.. and TM backup will corrupt. What will then happen is most likely the next time you attempt a backup on site you will get a message saying.
Time Machine must create a new backup for you.. see http://pondini.org/TM/C13.html
When you are on the move.. TM will do local snapshots.. or you should carry a 2.5" disk for local backups when away. Don't do remote TM.
Save important files directly to the cloud is fine.