Hi Jens,
A couple of things you should know:
1- Extreme Lagares is just around the corner (XL from KoEE), so most of the hardcore riders will be practicing and preparing the bikes. Are you coming to see the event? It is near Porto (Oporto) on the 12 and 13th October.
2- Geres is a protected area, be careful not to get a ticket, in the past I had to pay 265€ for that mistake., There are many good areas around Geres that you can ride, specially between Guimarães-Geres and Povoa de Lanhoso-Geres.
3- There have been a couple of bikes stolen recently so people will not be very open about showing a stranger where the keep their babies (bikes).
4- Normally we do not ride only 2-3 hours, it is either all morning or all afternoon, some even go into the night and arrive in the tarmac at 22.00.
I believe Milo-Rafael (forum members) can help you with the Geres part, they will respond if it is convenient for them.
Perhaps you can come along with me to Valongo (Oporto) on Sunday 29th from 15.00 until 22.00. One thing you need to remember is to respect the group logic, to have enough gas and oil, to be on time on the designated places.
We typically ride slowly but hard terrain (fast riders may get bored MX?? as you) and that it is always your responsibility to know your own limits (there are always alternatives, don't hurt yourself so that you do not affect negatively other people's ride).
There are many other good and friendly riders in this forum that can give other choices, such as faster programs (less time and more speed), I sure many here will volunteer... Also there are some enduro schools in (EnduroCode, TurresOffroad, etc) that can take you (whatever their price would be).
Continue to follow and ask and you shall find.
Kind regards
Foguette