That sounds like such a neat space for them! Whatever you decide that sounds like an amazing full-time set-up that they will be happy to go back to.
I've kept six (!) pigs in a 4x2 space for a week before (1 neutered male and 5 females) due to moving house (ugh) and I think one time during a flood when our house was in danger of, well, being flooded. :/ They all got along really well though and I spend a lot of time before I bond pigs together getting to know them and working out the best combination of personalities, so my groups are usually pretty solid and can tolerate each other even when I clean out their cages and pop them all in carriers, etc. I've made quite a few boar trios and a boar quad before, for instance, which I know is warned about on this forum and elsewhere! It's one of the perks of having quite a few piggies though... I know not everyone has the luxury of being able to personality match like that.