How to load this bike?

Hello!

Just got a Specialized turbo Vado 4, amazing bike. Got the e-bike as I have to take my son to school up some hills so it just made sense to me as he weighs a lot – also step through because it is so much easier to swing leg with him on. I absolutely love the bike and it’s entirely rideable without power too as it’s very light.

I will do some bike packing without him though. The bike seat comes off easily which is great.

I don’t want panniers as they’re more of a pain with the bike seat, even ones that clip to panniers.

I bought an Oxford aqua 10l seat bag already.

What else could I use for storage? It’s got a fixed front light which may stop me using a handle bar bag as it precludes from under the handlebars.

Any suggestions on slim tube bags which would allow a water bottle where cage is too?

What could I put on the top tube mounts?

Thanks!

David