I think 1.5°C is already basically impossible; scenarios between 2°C and 4°C by 2100 over pre-industrial levels seem achievable-- that would be a total remaining CO2 budget of ~3 Tera-tons of CO2 within 2100.

That is an average of 4 tons of CO2/person/year for 10 billion people. Americans are at 3x that right now, Europeans/Chinese 2x, and a few wealthy nations are already there (France, Switzerland, Israel). Poorer countries like India are significantly under that value (for now!).

Doubling that CO2 budget to 6000 Gt would make things significantly worse (5° expected temperature increase or more).