An external bluetooth GPS (I use an XGPS150) works perfectly but this raises two issues: AFAIK, there is no selection in any IOS app for which GPS to use the operating system will choose the internal or the external GPS and you can't see which one it is using, and can't force it to use just the external one, so it could switch to the internal one and then lose it...
AFAIK if you put the iPad in airplane mode it is unable to use the internal GPS. Now enable bluetooth and connect to your external GPS. Everything should work fine and you save a lot of battery not using the internal GPS. For some reason bluetooth uses much less power than the internal GPS.
Dublinpilot, thanks for replay and I am happy your get LKCL demise confirmed ;-) Unfortunately I have a direct visibility to this industrial zone at the moment from my office. I will have some more updates (not just removed airports), can we take it off line not to spam others here?