1) first and foremost - if you really care about the account then just don't bot on it. you will most likely get caught, especially if you're just getting back into it and you probably won't know how to bot smart right now.
2) a VPN shouldn't raise/lower the chances of you getting banned if you only plan on using one account. the reason you'd want accounts on different IPs is if you're running multiple accounts and don't want to raise suspicion by having them all on the same IP. mainly in order to cut ties between accounts, which should prevent a possible chain ban and also to not appear as a farm of some sort.
3) something that you MIGHT gain if you do bot on a completely different IP is that in case the account gets banned it will be more likely possible to submit a successful appeal and quash the ban (if you submit the appeal using your original IP, and not the one you botted on)