The Battle for Castle Itter occurred just before the official capitulation, and so is tangentially related, however, this may go toward your "fighters reluctant to surrender," point. It also happened five days after Hitler's suicide.

The Battle involved American soldiers fighting in tandem with German Heer soldiers against German Waffen SS soldiers. Yes- Americans and Germans fighting together in the Second World War.

The Castle was a kind of Club Med minimum security prison for French and other non-German prisoners with political or military cachet. However, it also served as the administrative center for Dachau. A Yugoslavian prisoner of the castle escaped to Allied lines. The Castle was surrendered by a German officer, Josef Gangl, who had cooperated with the Austrian resistance a little bit.

The rescuing force, combined with the Heer officers described, numbered only about 25 men, a German jeep ("kubelwagon"), a truck, and one Sherman tank. Having taken the castle, this scratch team was suddenly confronted by a force of Waffen-SS.

They numbered somewhere between 150-200 men.

They fought for about six hours. The Sherman was knocked out, so by the end of it there, it was really just 20 or so men versus ten times their number. After continuous, hard fighting, an American relief force marched to the garrison's aid and rescued the beleaguered multinational troops.

Josef Gangl was killed in the battle, but not before he and his troops made history as the only German Heer troops to ever fight on the side of the Allies.

A number of ports on the west coast of France remained under German control until the end of the war, the so-called Atlantic pockets, most notably in Saint-Nazaire. These ports had been heavily bombed, but as this region of France had largely liberated itself it was not deemed worth it to divert troops to conquer these last, heavily defended ports. Saint-Nazaire, for example, was one of the chief U-Boat bases and boasted naval as well as land defenses.

The Atlantic pockets were surrounded by the French Forces of the Interior for the remainder of the war until they surrendered a few days after the German surrender. Until then they were governed as the last outposts of Pétain's Etat Français. Cut off from the rest of France condition worsened within them until the end of the war, and a number of French inhabitants escaped or organized eternal resistance movements.

There was a German weather station on Svalbard, which held out for a few months after the German capitulation. Though that was due to the fact that they had no means of return to the continent and it took a while until a Norwegian ship turned up that they could surrender to.

In the Netherlands, there was a German force that was more or less left self-governing, albeit disarmed. For the execution of two German deserters, even after the general surrender, Canadian forces lend them rifles.

You should also look into the "Werwolf" plan. I know less of this, but the Wikipedia page - admittedly, a tertiary source not desirable by historical standards, but useful as introductory materials - describes the "dead-enders" fairly exhaustively.

Such as they were, these fearsome lycanthropes didn't have much staying power.