Free DNS subdomains via afraid.org is a great resource for lab and test machines.
They also have a free Dynamic DNS service which is a great way to keep tabs on your Home IP address in the event it should change. In the past I would use this to make sure I can VPN back to the house but now I have a OpenVPN server in a Data Center in Canada that I use.
Since I mentioned it, KimsUfi is a great resource for cheap servers. Pro Tip look for a “flash sale” to get a nice discount on your bill for as long as you continue rent the machine.