Why would you need two hands to remove the magazine? Grab mag, pull towards you on the magazine catch with index finger, remove mag.
There are also factory 5 rounders for the T3, as well as larger capacity aftermarket magazines. The bigger mags are stupid expensive, though - but then again, so are factory Tikka and Sako magazines. Or for that matter, just about any bolt gun magazine out there (or at least that's how it seems to me)... :/