My prediction is that the Dems barely take back the House in 2026, as the opposition almost always does, after the DNC pours money into unseating 'Centrist' Blue Dog Democrats with Progressives in swing districts. Republicans gain a 1-2 seats in the Senate with Kemp in GA and Sununu in NH. It's going to be a mirrored version of the 2022 midterms. Vance presumably will have a decent chance of winning in 2028, assuming Trump doesn't manage to tank the economy right beforehand, but it's going to be close unless the Democrats nominate an outright Socialist.
I would never count out the Democratic Party, as much as I wish I could. It's the oldest party in the world. It's the party of Andrew Jackson, Jefferson Davis, Grover Cleveland, Woodrow Wilson, FDR, George Wallace, JFK, Obama, etc. The party has shapeshifted for almost two centuries at this point to survive, to a point where none of its original principles are intact, and done so extremely successfully.