I think he'd be about 50/50, but I'd probably very slightly lean towards him losing, in part because PA Dems have a pretty decent bench. One data point worth considering is that Toomey ran ~0.6 points ahead of Trump in 2016, and Biden won PA by a point in 2020 (although direct comparisons aren't perfect because of different levels of third party voting).
Just quickly eye-balling the 2020 results in the PA suburbs, it looks the only district where congressional Republicans really ran ahead of Trump was in PA-1, where Fitzpatrick got 56.5% compared to Trump's 46.6%. As a PA suburbanite, my personal hope is that the type of voter who voted Biden/Fizpatrick would have realized that Toomey, unlike Fitzpatrick, is basically an average congressional Republican in terms of ideology (notwithstanding Toomey's occasionally centrist positions on social issues).
Actually congressional Republicans won the house popular vote in PA last year.