the Roads mysore - kannur are much better via mananthavadi. i had returned from mysore to kannur via mananthavadi . on 27th march. it was a breeze. i used this road as i had to go to muttanga wild life santuary short of sultan battery enroute. hyderabad to kannur via this road is 90 kms longer so i don't use this road to go to hyderabad. The road which i use to reach kannur from hyderabad in one day is . hyderabad NH 7 /NH 44 -devanhalli-doddballapur-nelamangala-nice road - leave nice road at mysore road exit- ramanagaram-chennapatana-maddur-mandya-srirangapatam-hunsur-gonnikoppal-perambadi-irrity-mattanur-kannur. total 940 kms leave hyderabad at 4 AM reach kannur by 8 PM. its hectic and tiring but finishes in one day. you can contine with your current plan of staying at bangalore . i do it in one day because i go to hyderabad on short leaves so halts eat into my leave period. another pointer is that if you are making it in one day, you would be driving in the ghat roads after dusk, so vehicle needs to be in excellent condition to have comfort of driving through forest area. by the way the forest check posts are open through out the night in this route. so make a choice and enjoy the drive.