It is indeed a pernicious problem, August! On the one hand, I think Wheel of Time is finally done. On the other hand, A Song of Ice and Fire looks as if it may not be done in my lifetime. Your only hope may be to stick with "open world" series (Valdemar, Darkover, and so on) where all the books are set in the same world, but the individual story is resolved in a single book or a trilogy at most.

With Sympathy,

James