I had a similar issues with weight using my IC7000 (2.3kg) plus 10Ah LiFePO pack another 1.5kg. Decided to switch to original M0NKA - mcHF QRP which gives me 12W on 80 & 40 and 10W on 20. I build mine, but you can order one, ready made from Chris M0NKA.co.uk.
My SOTA pack is now mcHF (0.6kg) plus 3Ah (0.5kg) and is good for 3-4hours on the summit. It draws 250mA on RX and 1.6-2.0A on TX depending on the band (SSB).
Good think about mcHF is that it is ready for DIGI modes, as it has all necessary bits inside. All you need is a USB cable to your tablet/laptop.