Use the DarkSky app. Apple owns it so even though you have to install it, it’s basically a first party app now and has the widget option and let’s you choose locations without enabling location services.
I have not tested any of these methods, but a quick search reveals the follwing apps / hacks that claim to do this:
iSpoofer - Claims to "Easily simulate any GPS location on your iPhone/iPad/iPod".
iTools - Claims to "Perfectly fake GPS location on an iPhone / iPad".
Source: How to fake a GPS location on your phone
A more complicated way of doing this ...
There's no way of explicity setting the update rate of your location. Note that you're not "communicating" directly with a GPS, but rather receiving location updates from Core Location that could come from a GPS source, but also from other sources.
Remember that the location updates are filtered to conserve power. This means that you only get updates when ...