Hmm... I'd say it really depends on whether you're someone who truly tends to benefit from staying super busy, or whether doing too much tends to be bad for your mental health (I know I'm definitely the crash and burn type, ha).

I'd also ask, would you have interviewed for the job if you knew it wasn't just part time/were you considering full time before? Don't feel pressured to take the job just because you've interviewed, if you don't think it's a good choice for you otherwise.

Good luck.