[Boromir88]

If I vote for Nonna then he will have 5 and Glirdan will have 6 (I hope I've counted right!)

You have, and that reminds me to add Farael to the list, as before I didn't see she voted for Glirdan, and she's the one that got it up to 6 votes.

Of course, it could simply look as though I am trying to save Glirdan, a task which looks very possible at the moment.

You and me in the same boat. This is the problem with voting when 1 or 2 people have the concentration of votes. If you're wrong it looks like you tried to save a fellow hero, if you're right...well it still looks like you betrayed your fellow hero. Which is why I think atleast one hero is in the group I mentioned above that really started to spread things between Glirdan and the rest.

And it's also likely that all the Elves have voted already, which would make heavy-analysis of the final votes all the more pointless.

It's likely, and in fact logically and mathematically likely that neither Glirdan nor Nonna our heros. Despite all this, I would still encourage you to vote, even if it's just looks like a throw-away vote at someone who has no chance of being devoured today.