Okay, those speeds are a bit on the low end, but should still be sufficient for some basic streaming.
This means the problem is with getting a strong enough signal from your router to the tv.
That can be the case even if other devices (laptop, tablet, phone, etc) are all working just fine on wifi. The wifi adapters inside these tvs are very small and underpowered, they are also heavily shielded by the metal casing of the tv, so their ability to pick up a good signal is poor to begin with.
Your best option here would be to move the router closer, or run a cord, such that the tv could be plugged directly into the router via a wired ethernet cable.
I realize that is not always practical though, so a next best solution is to use an external device to create a wired equivalent, such as using a powerline ethernet adapter or wifi bridge.
Just plug one into the router, other to the tv, and your connection should be sufficient to use all the apps, including netflix, on the tv.