Are the funeral services keeping the bodies on ice because they want them buried or because they're waiting for them to be cremated?
In this situation, where bodies are piling up, I'd understand the latter, but not the first. Then again (pardon my ignorance), I'm not from Spain so no idea what what the cultural thing in regards to funerals there is...
Yes, it's just temporary storage while they wait to be cremated.
Culturally I guess most people are buried, not cremated, and usually this takes two, three days or so. I do not really know how common is cremation in general, but I'd guess it's not the most common option -in normal circumstances-.