Six months. Not enough time for RII unless it happens in October (which we would win again), but long enough to replace May.
She won't go until after May 2nd, around three weeks away, and I'm sorry for the decimation of sitting Conservative councillors that will occur, but go she must. Members haven't had the chance to elect a leader since 2005, and given the schism between the parliamentary and ordinary party means there will be many Red Tories who will want another Parliamentary stitch-up to prevent the over 70% Brexit grass-roots party from finally democratically electing our Leader. However, the new leader will welcome the delay of a full election - the process won't be complete in time for the EP elections on 23rd May, which is likely to see both UKIP and the Brexit Party take many of the existing 19 Conservative seats. Thus the inevitable EP wipeout will still be yet another May disaster without tainting her successor.
Usefully also, party members are beginning to realise that the truly dreadful Hague party constitution is in deep need of reform. It is a patrician stitch-up that institutionalises the power of the party grandees and reduces members to the level of dumb leaflet deliverers. A petition of members will need 10,000 signatures to start with just to change the 12-month rule - to twist May's arm if she digs her fingernails into the Number 10 door posts. Where do I sign?