Sprite as Thumbnail and Full Image - duplicate sprite?

I want to have an image in 64x64 and 1024x1024 dimension. 64x64 for thumbnail and 1024x1024 for full size image. I'm loading images from resource folder on the fly.

Solution 1:
Create two copies of each image - one compressed as 64x64 and other as 1024x1024.
Issue : higher build size

Solution 2:
Keep only one copy -1024x1024 and assign same image to sprite renderer/4.6 Image.sprite in both cases.
Issue: Thumbnail view takes very high memory as it is showing thumbnail for around 100+items.

What is the best way to have one image in build and multiple replicas in memory while loading? Can I specify sprite max size when loading in memory from resources?

 

Ping

 

Anyone?

 

Anyone?