Sent a student on a 1st solo in a healthy 8kts straight across recently, very nice job she made of it too....
You will need to be able to deal with stronger. As with many skills in flying- best achieved by nibbling at your limits in order to extend them and always remember that after any lay off you won't be as good as you (recall) you were the last time you flew.
If you are flying with someone with higher limits (e.g. an instructor) then you can probably take bigger nibbles and raise your limits more expeditiously - and therefore more cheaply.
Do you have any articular objection to building up to a higher limit by flying dual?
PF