Portable seats and weight thresholds

[ScratchedSkirtings]

Hello!
we don’t have a car (and our house is small), but are looking at leasing one for May- September because of quite a lot of complicated travel coming up (including outside the UK)
we have thee DC:
age 3, 17.6kg, 102cm
age 6.5 (not near any thresholds of height/weight, phew)
age 10, 147cm

Car seats we own are-
incredible inflatable nachfolger ERF , up to 18kg and 105cm. I love this seat.

Enormous Britax Evolva 123 FF, with 5 point harness up
to 18kg, seat belt thereafter (now 9 years old)

Britax Romer high-back booster

Hi-fold foldable high back booster which goes up to 150cm +
—-
we can currently (just) squeeze into a Golf with DC3 in the Nachfolger, DC6 in the Romer, and DC10 squeezed in the middle in the Hi-fold, with a bit of praying and wriggling to get him buckled in.

There seems to me to be no advantage to the 123 over the nachfolger- as once DC3 is out of the ERF she will also be too heavy for the 5point harness on the 123?
space-wise we get much more flexibility with DC3 in the Romer, and both older kids in Hi-folds. Although it looks like the hi-fold is discontinued so getting a second one may not be the easy solution I thought it would be…

what would you do???

I'd probably let the 10yo go without a seat, they should get a good belt fit in the majority of cars now. If it worries you, something like Bubble Bum might be a good, compact solution. Some EU countries have 150cm / 12 as their limit, but most have a higher limit of 135cm (like the UK) or 10 years (e.g. France) so you probably are OK most everywhere. And most countries have an exception for the middle seat if you have 2 kids in child seats anyway.

How is DC3 for height in the Nachfolger? The Evolva has quite a generous height allowance as 123 seats go, so it might be useful just to bridge a gap. I'd compare them to each other (remember, rear facing harness can go up to 2cm below the shoulder, whereas forward facing must be level or slightly above). If you have the same capacity in the Nachfolger, I'd probably tip that one now (at 9 years old, it's too old to pass on to anyone else). If there's an extra couple of centimetres in the Evolva it might be worth keeping hold of just in case.

However, with 0.4kg to go it might be that she's too big for both soon anyway. Keep an eye on it - they can put weight on in fits and spurts so she could hover at that weight for ages and reach the height capacity first. (Though weight capacity does seem more likely).

Is it the Britax Romer Adventure you have? It's a bit iffy to put a 3 year old in a high backed booster realistically - you could give her a trial fit in it to see. She is the right size physically, but it's whether she would sit sensibly and not fiddle with the belt or slouch. Some (but not all) children on the older end of 3 are fine, I've not seen any on the younger end of 3 who sit properly. I'd be happier with this than the Hifold though for a 3yo, because the Hifold didn't get a great crash test rating, it's basically the same as a backless booster for safety.

So you could do DC1 without seat / in bubble bum, DC2 in hifold, DC3 in Adventure (or Nachfolger if it still fits).

Or Adventure/hifold for DC2 and look at a different seat for DC3 -

Have you seen Chicco Fold & Go? That might be worth investing in, it's slimline, more up to date than the Britax Adventure, meets the newer safety standard, and has an extra hook for the lap belt so in theory (?) might be better for wriggly toddlers. Lasts up until no longer needing a seat as well.

Unfortunately the only thing remotely portable with a harness over 18kg is probably Cozy n Safe Hudson, and that's not really a travel seat (though I think it's a bit slimmer than Britax Evolva).

Sorry I've used older convention for DC1 eldest, DC2 second child etc. Just realised you were using the age version! Hope it's clear.

thank you so much @BertieBotts - very clear, and hugely helpful! I usually say DC1,2,3 too, just went for ages as it was relevant.
I’d not looked at the Chicco, it’s new since I last researched, it looks like it could be just the thing, thank you! The Britax Romer we have is the Kid II (and DC2 is actually at the top setting on it for height). DC3 isn’t in cars often- but actually I did a very short Zipcar drive with her in the Hi-fold (I grabbed the wrong mystery-black-carseat-bag and only realised when I opened it in the car, 10 mins walk away, late…) and she was good as gold, and comfy (phew!). I wouldn’t for a longer journey though! She’s pretty close to the limit height wise on the Nachfolfer, sadly. I suppose if she ends up using the Evolva briefly it will make it worth having hung onto it for the last 3 years…
so potentially- DC3 in the Evolva/Nachfolger, DC2 in a Chicco or the Kid II, and DC1 in the hi-fold if it fits, or nothing- and once DC3 hits 18kg, she can bagsy the Chicco. And I tip the Evolva and regain the use of my hall cupboard!

Sounds like a good plan!