Can someone, preferably with experience of the area,
shares their thoughts on what the soaring is like in
the Minden area in late May-early June?

It can be great and it can also snow. I remember dodging snow coming from the
*Q* I was working in region 11 contest held over Memorial Day (late May). We
now hold our contest in mid June. By 4 July, thunderstorms may become a
problem. On the other hand 4 guys flew 1000 K in late May about 15 years back.
You pay's your money and takes your chances.
:(
JJ Sinclair