Note that this is a different location than the OGC Technical Committee meeting. Both are around Toulouse city center and easily accessible. They are a 15min ride or 40 min walk apart.
Organizers do not specifically recommend one hotel. That being said the Capitole, Toulouse mains square, is ideally situated between INP-ENSEEIHT hosting the hackathon and the congress hosting the OGC Technical Committee meeting. The hotels are of high standing and will accommodate most. Other more affordable options are available closer to INP-ENSEEIHT but with limited places so we recommending booking those now. AirBnB also remains an interesting alternative.