do Rishiri/Rebun worth to go in winter

I plan to go to Hokkaido in 9-21 march 2015.

I like nature and I found that rishiri and rebun island in summer is very greenish and beautiful. But I have no idea in winter. I cannot find any picture or review on the internet.

Please suggest whether these places are worth to go or not

Thanks

Most places to stay on the islands are closed from October through April as hiking and flower observation are the main attractions. The Momoiwaso Youth Hostel is only open from 1 June to 29 September to give you an idea. In addition, in winter, the seas get rough and the ferries can cancel, leaving you stranded (there are only 2 ferries per day in winter from Wakkanai). Tourist buses start in May at the earliest and run until early October at the latest. It's pretty cold and windy there in the winter, so few people go. I've tried to get there in early May but didn't make it due to weather. I haven't tried in winter.