I've dropped a bag at another airport a bit outside of the two hour window, but of course YMMV. I'd recommend not to worry too much about Wizzair and LTN.

The travel experience with Wizzair is in my mind very similar to Ryanair or Easyjet, with the notable difference that a fee applies to larger cabin baggage (and there is no additional 'personal item' unless you buy priority boarding). As long as you are aware of that and pay for what you need in advance, all should be fine.

LTN has seen quite a few improvements - depends of course where you are traveling from, but travel time should be somewhat predictable, either by taking the train and then the bus shuttle, or by checking current traffic conditions. For added peace of mind, you can pre-order fast track security through the LTN website for £3.