Can I upgrade my wallet in the future, like 1-2 years from today?
I am a long term holder, I've been holding for over 6 months, I have not open since the day I created it and added bitcore funds to it. I only check my balance when needed via
https://chainz.cryptoid.info/btx/ knowing it's still there

and recently I checked my converted address since the old address is empty.
Thanks all in advance

We are all
mid-term holders because none of us holds BTX since more than 3 years. Many of us will eventually become
long-term holders in the year 2020.
As the BTX coins are "stored" in the blockchain and not really in your wallet,
my take is that you could still upgrade your wallet software in 1-2 years, as long as you have your private keys.
So make sure you have a backup of that wallet.dat on a cold store (i.e. USB stick in bank safe), encrypt your desktop wallet,
and write down that wallet encryption password (also place that one in bank safe).