>Ask original question
>
>Is sleep harder to resist than other spells?

It's never harder than another spell save from the same caster and often easier.

>Things I've tried to do.
>
>Spam waiting for summon/arrival

Helpful.

>Sleep a couple hours before moving in on them.

Not helpful. Possibly counter-productive depending on circumstances.

>Uber Saves vs Spell

This helps a lot.

>End result = Slept summoned to locked room Soaked left to rot
>or killed out right.

You probably should think twice about getting into a fight with a necromancer if you're in an area where this could happen. I'm not saying don't do it, but think about it.

>I;ve killed a number of them over the years, but f they are
>able to get a sleep off, and they seem very capable of it,
>that's the end more often than Not.

The single best defense against being beat by sleep like this is (no, not teleport potion, although that's and related goodies are also on the list) is having a competent ally aware of what's going on. If I sleep you and your buddy just words you or murders you to wake you up, I haven't really gotten anywhere.

Another strategy is to make sure every necromancer who attempts to sleep you either dies or damn near dies, or is unable to cast sleep again for whatever reason. I have a very hard time remembering a fight I've had with a sleep class in recent memory where I let them have multiple chances at sleeping me.