Hi and welcome.
I would just like to give some advise also.
Folders are very different from each other. Obsoltuley make sure you test ride before buying. However it may be worth buying a know product that can be resolded if unable to do this. Ie bromptons are not a risk as resale pricers are excellent.
There are some fantastic bikes out there, which might be in budget used. Ie birdie or dahon jetstream. Downtube fs is excellent I know nothing about oringimi bikes.

There are a few posters who have several folders for family outings. Great in a moderate sized car. I have four different folders for this purpose. Another forum user has 5 mezzo.
Go for it! choose carefully possibly tring one bike for a while before commiting to another. Make sure you have all the familes aproval, as children can be picky about bikes also. Its makes it easier if children like the bike to encourage family rides.