I looked at my home server setup and found a troubling problem. It's running squeeze in NAND and works basically fine. But Debian no longer gives security updates (for i386 and amd64 it does still), and suggests: Users of other architectures are encouraged to upgrade to Debian 7 ("wheezy")

This is problematic because wheezy is substantially larger than squeeze. For raw numbers, a base setup after stripping out much is 278M for squeeze and 486M for wheezy. That's a huge difference. After installing needed software on both setups, squeeze can still run in NAND with 60M free (uncompressed), and wheezy is already out of bounds.

Are there any Debian alternatives to get updates short of periodically compiling my own out of git?

What about other Distros? Gentoo seems to keep all that up to date, but it's not really my forte. I have no idea how large it gets either.