Hello welcome to the Forum, you have picked a challenging plant to try and grow and I will try and give you some guidance.
![Raoulia eximia 648736-0](https://www.srgc.org.uk/forum/index.php?PHPSESSID=e13371994f45f06d0686a5291ac7b73b&action=dlattach;topic=17302.0;attach=648736;image)
I cannot say what the minimum and maximum temperatures it can tolerate are but I have grown a number of plants in pots kept under glass in our cool Scottish garden. There they would have been exposed to winter temperatures down to at least - 12C and summer temperatures in the glasshouse up to 30C. I would say the most important thing is to keep it moist at all times especially during the growing season.
![Raoulia eximia](https://www.srgc.org.uk/forum/index.php?PHPSESSID=e13371994f45f06d0686a5291ac7b73b&action=dlattach;topic=17302.0;attach=648738;image)
I did this by breaking the commonly given advice that you should not to water over head, I always watered this way making sure that the plant never dried out - for this to work it is essential to have a well drained potting medium.
Good luck.