It will really depend on what is standard in the geography area. Higher end markets/properties in high demand will ask for more.
I have no propblem with first/last month being paid up front since I will have to pay it eventually.
If you do put down a deposit then be sure that you know what conditions will mean you don't get it back. What happens if things fall through and you cant go this winter? Be sure to take lots of pictures and document things that are damaged when you get there so you don't end up paying for repairs that you didn't cause. Get the landlord to acknowledge those things up front.
I havent seen a deposit for holding a place. Once you sign the lease agreement that's it. I would imagine that a hold deposit might not be given back if you decide not to take it so I'd take the risk of not getting the place and not pay it.
"We can judge the heart of a man by his treatment of animals" Immanuel Kant