Some carefully placed water buckets might be able to hold them just out of range of hitting you with potions long enough for you to get past them (lava works, too!), and then follow general advice for hurrying up the process of them simply de-spawning. 

I've been base-blocked by witches and [skeleton traps][1] more than a few times early-game, and water buckets came in handy. I tend to settle into the first plains biome I can find, at least early on.

They're _much_ easier to kill with a ranged weapon, but some water might keep 'em _out_ of range.

Also, don't forget ender pearls if you just want to make a quick escape for chunks to have an opportunity to unload. 

  [1]: https://minecraft.gamepedia.com/Horse#Skeleton_trap