Personnel from several teams fought a blaze that began 90 minutes after Maldonado had given Williams their first victory for nearly seven and a half years.
Three from Williams had to be transferred to local hospitals, with two having now returned home after receiving treatment for smoke inhalation.
The one person still in hospital suffered burns in the incident, but is stable and will return to the UK within the next 48 hours to receive further medical care.
Williams added the team member concerned is “in good spirits”, and that his family are “in constant communication”.
Team principal and founder Sir Frank Williams said: “I was pleased to welcome back to the factory the majority of our team this morning. One of our people remains in Spain for further medical assistance, but we are all looking forward to his imminent return.
“Everyone at Williams F1 is extremely relieved that this event was contained as quickly as it was and the damage which occurred was, relatively speaking, limited in its nature. While the incident was unexpected and definitely most undesirable, it has demonstrated the genuine cohesiveness, camaraderie and spirit of co-operation that exists within the Formula One paddock.
“The astonishing response from the teams and other paddock personnel was immediate, unconditional and overwhelming.”
Williams further stated investigations into the cause of the fire are on-going in collaboration with the FIA and local authorities.
Earlier yesterday, Williams chief operations engineer Mark Gillan extended the team’s gratitude to their rivals for their help in dealing with tackling the blaze. “On behalf of Williams, I’d like to thank all of the team members from other teams for their help during the fire,” said Gillan.
“We were overwhelmed by the support. It was really impressive. Williams would like to say thanks to the teams, the FIA, FOM and all of those who came to help. It was a serious issue and I am very grateful indeed.
“What happened after a great result is very disappointing, but things were limited by the fast response of our team and everyone who helped.”
Gillan expects Williams to be back up and running at the Monaco Grand Prix next week, despite losing a considerable amount of equipment.
“We had a lot of damage and we have lost a lot of equipment, including IT equipment,” said Gillan.
“Over the next couple of days we will be looking at where we are parts-wise. We will have everything we need to run operationally at Monaco, but we may be missing a few of the extras because obviously we don’t carry a complete set of spares for everything.”