Not being able to pay for Secret Service protection anymore: it’s a feature.
Trump has his own private bodyguards in addition to the Secret Service. If he taps out all of the Secret Service funding and they are no longer able to protect everyone in his circle, his people will then be able to move and meet freely without witnesses that haven’t sworn personal loyalty to Trump. That has in fact been the primary benefit of the Secret Service in the age of Trump – a cadre of nonpartisan witnesses always close at hand.
If I were Congress, I’d remove the annual pay caps and maybe provide extra people from the FBI or US Marshalls, since they’re likely going to need to be nearby eventually. But then I’m not Congress.