I think they are playing a bit of a longer game, but the history is what it is.... President's typically lose seats in a midterm, sometimes quite a few.
What I would suggest is that because, for better or worse, there's so little daylight these days between a President's JA and voting intention for Congress (because of polarization), that could redound to the D's benefit in the event that Biden were to go up from the 42-43 that he's at now up to around 49-51. But that's gonna require changes to the status quo in terms of inflationary pressure on things like gas prices or food costs (ie. things people notice)... not to mention on COVID
I will say that the tendency of political pundits to look at everything going on right this moment through a midterm lens despite the fact that we are a over 11 months away from the midterm probably undersells the possibility that we may be debating an entirely different set of issues in October 2022.