I use Tesco, who used to allow 90 days. We need to keep with them because of treatment and a new insurer would say (rightly) that it's a pre-existing condition. Last year at renewal they changed it to, I think, up to three trips of up to 30 days each. I called them and they said they were quite relaxed about rolling the three together. I wasn't too happy but we didn't have a holiday planned at the time. However when we were planning to go away I called them again and they again said it was fine. So at least they are consistent. We didn't have to claim though!