When you have an HD wallet does that mean you're safe as long as you have your seed saved somewhere? Also how often do you have to extend the seed if at all?
HD wallets allows for the generation of addresses from a single seed. As long as you have that seed, you just need to make a single backup. There should be virtually no limitations on the amount of keys that could be generated from a seed.
I'm thinking of converting my wallet to an HD one, I'd probably have to pay a decent fee to consolidate my funds but I'm sure it's worth it for the extra peace of mind.
You can always consolidate when the fees are lower. HD wallets do provide much more convenience over older wallets and you won't have to make frequent backups to your keys as well.
If there's an option for seed phrase, even better. Paper backups would be even easier.
What wallet are you using now?