my .02...
i've had a 8x16 ice castle and a 6x10 zack shack, along with 3 others i've built...
the zack was great for fishing, not so much for entertaining... it set up easy enough for 1 person to move daily, but was not fancy...
the ice castle was great for entertaining and fishing, but not for moving...
the 3 home made ones were b4 wheel house frames were available, and were built with pull out axles, and moving was dangerous at best...
if i was you, and was close enough to help him move it when it had to b moved (think 30" storm coming), i would probably push for something nice like an ice castle, new or used that he likes... if i wasn't able to get there to help within 24 hours if needed, light and manageable would be my recommendation... we had to burn 1 off cuz i couldn't get back to help move it b4 a storm... was a really sick and defeating feeling...
don't wait would be my biggest recommendation... we had looked at the ice castles years... when we finally bought 1, he fished in it 2 short days b4 dying of cancer... never waste a day...
good luck...