Saw a couple of the Aerofit Bike box Alans on my last Mallorca trip - they are massive.
Another option might be - https://sciconsports.com/uk_en/aerotech ... p070200544
Looks to be more compact and works with semi-integrated bars - it does require you to be able to rotate your bars around though.
Personally I've bad bad experiences with soft bags and wouldn't use one again.