Will rates be able to remain in the comparatively great territory they entered last week, or does Friday's post-NFP sell-off mean we should be fearful of a big retracement back toward levels from earlier in Dec or worse?

Neither I, nor anyone else can tell you which of those options is more likely to play out, but I can suggest a few ceilings to consider in the process.  There's a more optimistic ceiling just overhead around 2.68-2.69.  That would be the best case scenario as these were the highs from Friday and from the overnight session.  If that's broken, all hope isn't lost, but we'd be looking at a moderately big jump up to 2.81-2.82 for the next major support.

2019-1-7 open

In addition to trading levels themselves, we'll also be watching momentum metrics for the eventual spike in short-term momentum.  Take a look at how the momentum lines were behaving in late August.  That's the sort of thing that would confirm a shift toward higher rates (though it wouldn't comment on how long that negative trend would last).

This week's important data is fairly well dispersed.  The two biggest reports act as bookends with ISM Non-Manufacturing this morning and CPI on Friday morning.  The intervening days don't offer much by way of economic data, but they will play host to the 3,10, and 30yr Treasury auctions.  These provide an opportunity to gauge investor sentiment regarding bonds in a much more liquid environment than late December (which proved to be challenging for the last round of auctions).