Bikepacking bag capacity

I am making the switch from panniers to bikepacking bags and I have some questions regarding capacity and the shape of things I need to pack. I have reviewed the whole forum.

Capacity is fairly easy to gauge as I know the capacity of the panniers that I have used in the past and I can see the capacity of the bags listed at a retailers site. The shape of the bags is quite different so I am hoping to get some ideas on my set up from some of you who are already using bikepacking bags.

I should add I am more of a Bicycle Tourist than a Bikepacker as my trip will mainly be on pavement. I travel ultralight and see the benefits of a streamlined bicycle as driving this change. My bicycle does not have rack mounts either and I hate using c-clamps to mount a rack.

I would be getting the largest size bags I could find.

Handlebar harness - I look at this and see how it could handle my whole camping set up immediately: tarp, bivy, bug net, sleeping bag, sleeping pad, warm socks, hat, and a wool baselayyer would all role up into a nice stuff sack and fit right in the harness…PERFECTLY. I like having all of my camp gear in one spot so there is one bag to deal with when it comes time to set up and break down. Some add on pockets for daily needs items: sunscreen, camera/cellphone, lube, patch kit, etc. I completely get the idea and love this. maybe I might strap my rain gear on this as well.

Seat packs - I am not sure how easy this would be to get things in and out of, and I see the shape making this a challenge to pack. I would probably carry all of my clean clothing at the very bottom followed by a stuff sack with dirty clothing as the next layer. On top of that maybe my toiletry kit, stove and food. It would be helpful for me if someone could compare "a household object" that I am familiar with to a fully packed seatbag. I might wrap two extra tires around the outside of this.

Framebag - 6L Water, tools, pump, tubes, bike cables, electronic chargers/cables, first aid, etc. I get this but want to know if people miss having bottles and cages. I have never used a bladder or dromedary bag for water…any info on what the transformation was like would be helpful.

Gastank & Seat tube bag - Small stuff that will not fit into the handlebar harness - daily needs.

Any experience, both positive and negative, with the transition from panniers to bikepacking bags will help me out a great deal.

So far this has been a very informative forum on a topic I am greatly interested in....so thanks...I endeavor to help the community here as much as I can.

Thanks in advance.