I do personally find grinding 5-1 at the end of the month easier than 15-5. Never hit legend, but have been close. Last month hit 3 full stars with 90%wr and didn't hit legend cause I didn't feel like playing on new years eve.
Thanks for the encouragement :) but I think it's time for me to stop the attempt. After My short trip to rank 1 I'm back to 5 zero stars now. Maybe I just try it again in a meta I enjoy a bit more..but warlocks and priests currently make me rage whenever I see them.
I was in your spot last month. I ended up taking Murloc Pally from 4 to Legend. On 12/30, I was Rank 1-1 and ready to put in some extra time to grind. Ended up going 5-0 right away. The adrenaline and excitement when the Priest said "Well Played" on turn 5 was amazing.
Take your time. Take breaks. You already know you can win with your deck. You can do it!