I believe Saturday at CGK is actually less traffic unless you go to area with mall (Plaza Indonesia / Bundaran HI comes to my mind)

for convenience, mercure pik is good option as it very close to airport and plenty of food around. Pool wise its very average.

Pullman cp is another sound suggestion. No idea about their lounge and pool as I never try them. I stayed at pullman cp before though. Their mascot ... the "thing" is creeepyy 😅