Have a plan B.
Thanks for the replies. The first riding day will be the longest at about 423 miles. I will be purchasing a gel pad soon. The rest of the time it is 250 - 300 so not bad. I ride all year round and have checked temperatures for the last few years and it will be 10 - 15C so not too bad at all. I will be on the main roads for most of it, but if I see something worth checking out then I will go on smaller roads. There is no mad rush to get anywhere so leisurely riding will be the main thing, but hitting a few twisties then the GS can have some fun HeHe!
Sound a great trip, lots of riding but if that's your thing then it's perfect.
Please accept the following in the spirit in which it was written. My comments are based on actually living in the Alps, our village is at 850 metres with mountains around rising to 3,300 m. We are in Austria but similar conditions apply throughout the Alps
I think you need to remember that these were almost certainly average temps. and by the looks of it average highs. It can indeed be mild in the Alps in March, last spring was so warm here that local bikers were getting their bikes out early (you get a discount here for giving up your numberplate in the winter months) The previous year it was early April before it was safe to ride, the year before that late April.
One of the biggest problems with early season riding is the amount of grit left on the roads. It takes a few weeks for it to clear-cars push it into the bends and gradually the rain washes it away.
I'm not trying to put you off, if the weather is mild you will enjoy it, I'm just saying have a plan B in case you hit a cold spell.
Alpine weather is unpredictable at the best of times. We get quite a few people coming to our place via the Grossglockner and we always advise that they have a plan B in case of bad weather or just snow on the high roads, even in high summer.
Have a safe trip and enjoy.
John