Booster with slimmer base width and padding?

[EALOVE]

My 6 year old currently rides full time in a Graco Affix, in the middle seat, middle row of my 2011 Odyssey. She loves the seat, but it now complaining it's hard and is hurting her back.
Due to lack of funds I haven't been able to get the ProBooster yet that I've been so wanting. We are soon going on a 12 hour road trip (as we do a few times a year) and now I will have to get her something better before we travel.

My only issue is that I prefer to keep them 3 across in the middle row, all the time but especially for the trip so we can leave the back open for luggage, presents, stroller, etc.

Can someone tell me the external seat width of the Diono Cambria? I read our Affix has a 15.5" width so I'm hoping to get a comparison. How is the padding in it? Is there another more comfortable with a comparable width to the Graco Booster? I can do a Combination if need be since I have a 6, 4 and 2 year old.

I currently have a 4 year old FF behind passenger in a Marathon, boostered 6 year old in middle and RF 2 year old in True Fit Premier behind driver.

 

[MotoMommaNH]

I haven't seen one in real life, but a previous poster said the Cambria is huge. Like super wide.
Have you looked at the Britax Parkway?
Do you have the six year olds stats? Maybe we can make a more tailored recommendation for a booster or combo seat with that info.

Sent from my HTC using Tapatalk

 

[EALOVE]

Thank you!
She's currently sleeping but based on her last stats Id say she's approx 44-45" and 43#. She turned 6 early October. Not overly leggy, pretty proportionate. She fits well in the Affix.

 

[EALOVE]

Her stats today are 45#, 45".