but will it give me any serious issues such as freezes or full on crashes?
More probable that you will get low fps or that your strategy game turns into a crawl if the CPU can't keep up.
I doubt you'll be able to get a new cpu that fits your motherboard socket though, so unless you find one second hand you'll end up replacing the motherboard and your memory too if you try to upgrade.
https://www.bbc.com/travel/article/20220112-nowa-huta-polands-utopian-socialist-city