A really useful resource for approaching your question is the Open Domesday Project, part of which is a digitised map of every settlement named in the 1086 Domesday Book (although admittedly omitting cities and major urban centres). As you can see, travelling 50km wouldn't just take you to the next settlement, but far, far past it and probably past several others as well. Where you get a greater distance is between the Burh sites which, by the late 10th Century, had evolved (or were being evolved) beyond their initial military function into civil centres and mandated sites of high-value trade (see Æthelstan II). Nonetheless, these are still no more than 40 miles away from each other, so that no settlement was more than a day's march from relief by a garrison force. Unless you were travelling from burh to burh, therefore, you're really unlikely to be travelling more than a day. In fact, if you're making a short trip, say, to market in the nearest large town, you might have an early start and a late return but you'd probably make the whole trip in the same day.

A useful illustration can be seen in The Book of Margery Kempe, where Kempe illustrates an anecdote in which she and her husband walk home from a market:

It happened one Friday, Midsummer Eve, as this creature was coming from York carrying a bottle of beer in her hand, and her husband a cake tucked inside his clothes against his chest...

As the rest of the anecdote suggests, this is far more of a casual walk than a long-distance hike.