He Nekitfox,
I live in the Netherlands, (so CE country) and bought a Spark recently. Whenever flying, I would reach the connection limits disappointingly soon. When flying around a tree that stood a 100m away from me, I would loose video feed.
Due to the regulations in certain countries, the Spark will fly in CE mode, which limits the amount of channels and I think also the power of the connection between the drone and the RC.
With this limited connection strength, the connection can become frustratingly susceptible to disturbances such as bluetooth signals and physical blockages (such as trees, buildings, etc.)
In order to make the connection less prone to drop, you can fly OTG, which makes the connection between the phone and the RC stable and I think it also frees up some channels for the communication between the drone and the RC (but not sure of the latter). I found that flying OTG did not add much reliability to the connection.
On top of that, you can fool your drone into think that it is in the US. When you do so, it will switch to the US connection settings, which should give you a much more powerful connection, leading to less connection drops and/or increased range. Strictly speaking, this would probably be illegal though, so it is at your own choice. If you want to find out how to do it, look for "FCC hack" on youtube.
Cheers mate, and hope it works out well for you!