Have Buddhas escaped samsara?

Have Buddhas escaped samsara? Obviously there is the mainly Chinese term "non-abiding in nirvana". I'm interested in an answer from any tradition at all, and for enlightened non-Buddhas, too. To be specific, I would like to know if when a Buddha dies they then *suffer* death, or whether their death is somehow something over and above the suffering of samsara. I'm asking just because I think that's how I'd like the near eternal rounds of rebirth to end, perhaps with a little regret. Cheers.