Regards DOGE, I doubt they'll have authority to actually do much, but can make recommendations to DJT. My hope is they can A) ferret out the few agencies that should be retained, allowing Trump to close the rest, and B) figure out the % of workers actually needed at whatever agencies remain. If (IF) it goes the way it should wed probably see 70-80% of agencies eliminated altogether, and staffing at the remainder drop by 50-80% as well, for a total head count reduction of at least 80%, and an ability to sell off 80-90% or so of federal buildings.
Things like DoD, courts, probably SS, some regulatory bodies would remain, but with staffing much reduced.