Hi Jenny,
About a month ago, one could only get from South Gate to Xakanaxa, and then from South Gate to North Gate - one could not go directly from Xakanaxa to North Gate. You could not reach Khwai camping area (Mmogotho) from North Gate, you had to take the transit route to Mababe village and then to Mmogotho.
But that was a few weeks ago - Botswana is still getting some rain, but not that much, so by May it should be drier. However, Angola (catchment area for the Okavango river) is receiving a fair bit of rain this week - so come May/June/July the levels in the delta may change things again! October should be dry enough.
Best would be to check on the FB group DriveBots, and the Moremi Game Reserve sightings pages for recent updates - and when you travel, always ask the rangers at the gates, they will advise on the best routes to take.
Hope that helps, enjoy!
Regards/Groete
Lizette
Lizette Swart