I've been using Electrum 2.5.4 since December 2015. Electrum is "my first" wallet, as I had been using Blockchain.info which, as a web based wallet, I can't really consider mine.

I've built a cold wallet using an old laptop and, since I plan to keep my stash for the long haul, I don't really want to touch my wallet very often. All I do is have an Electrum installation on my primary PC in watching mode.

Now let's go to the very reason I'm writing.

1) In the case I never updated my cold wallet version for, let's say, a few years, what would happen? Could I simply download the new version and recover my money by using the seed generated with my n-year-old version of Electrum?

2) If I regularly update my Electrum version, is the seed always valid? My concern is that, at some point, the old seed wouldn't be recognized and the wallet would get compromised.