I think we have to assume that the deportations from Hungary are stopped. IOTL, about 450,000 people were deported between May and July 1944, and most of those were sent to the gas chambers on arrival at Auschwitz. The Nazis wouldn't, and couldn't, keep alive the people who were able to work alive within the camp system, let alone those who weren't.If the gassing stops the death camps are going to get rather crowded. I’m assuming instead that you mean the policy of execution without labour is stopped. Because if you just stop the gas you’re going to get starvation trains and death marches into Poland.
If the situation in Hungary progresses as IOTL, many people will still be killed by the Germans and the Arrow Cross. However, I don't think that's the most plausible way to bring about what the OP has in mind. The Nazis aren't going to stop gassing people in May 1944, and they're not going to stop killing people until, effectively, after the capitulation. It is, however, possible for the political and military situation in Hungary to change in a way that prevents the deportations.
The Hungarian Jews are the largest group that was killed in the extermination camps after May 1944, and the only group that I think could realistically survive. Rural Jewish life in Eastern Europe was already wiped out by May 1944; every Jewish person alive in occupied Poland at that time was in the Lodz Ghetto (to be destroyed within a few months), in a concentration camp, or in hiding.
If something changes with the Lodz Ghetto, then there's a chance Chaim Rumkowski might have a fate other than death on arrival at Auschwitz on 28 August 1944. He was a tyrant and likely a pedophile, but he kept the ghetto open as a slave-labor factory longer than any other. (There are three theories as to how he died: being deemed unable to work and sent to the gas chambers on arrival, being beaten to death by Lodz Jews from the Sonderkommando, or introducing himself to the SS as the ghetto's leader and given a faux tour of the camp before being thrown into the crematorium pits.) My suspicion is that he eyed a political career in Israel. I seriously doubt that he would have survived until 1948 -- but his fate, really, is its own what-if.