Conditions A Stroke?

I haven't been on here in ages. My old username was DraDra... I'm not quite sure why I can't remember my password. Anyways, I have a really odd scenario, and I'd like your advice.
My guinea pig, Mailen, was healthy and normal until Wednesday morning. I woke up and found him laying on his side. His eyes and nose were crusty, and he couldn't get up. When I tried to help him get up, he wobbled and fell back on his side. I had to go to school, and he stayed with my mother in a shoe box (he couldn't move, and we didn't want him in the same cage with his cagemate). We all thought he was dying and there was nothing a vet could do. I thought it was a stroke. Is that possible? When I came home from school, I gave him some water and lettuce, and this time when I helped him up, he stayed up. At first he was resting against the bedding in the box, but eventually he was able to stand on his own and shuffle around. We were all appalled at this new turn of events...
We put him in a pet store cage (he still wasn't able to move around quite as well, and the size was adequate to his needs). His eyes and nose cleared up, and he's eating and drinking normally. I lifted him out of his cage to clean it, and he was moving all four of his feet normally (previously, his left back foot appeared paralyzed). I let him wander around for a little while, and it still seems like he's using all four feet normally, and it's not just my imagination.
Would putting him back in the 4x4 with his cagemate be good for him? His nose and eyes aren't crusty anymore, his breathing is normal, and he appears to be perfectly healthy. However, I don't want the stress of the larger cage and his buddy to give him problems. What would you do?