For remote battery-powered data logging, if it's really required that the timestamp be accurate, I think it's possible to use an RTC and have an extended sync interval - maybe up to a year. But you have to take into account the things that are most likely to prevent that - variations in temperature and power supply voltage.
Even if the RTC can be powered by the battery directly, with no regulator, it may make sense to use one to avoid any change in voltage as the battery discharges. So for example a 3.0V, or even 2.8V, regulator might make sense for powering from a single LiPO, or multiples in parallel.
But the big thing is temperature, particularly if "remote" means outside. The DS3231 RTC has built-in automatic temperature compensation, but I've never tested how well it works, and have not been able to make sense of the datasheet diagrams on that. But I have a setup that sets the aging register to the value that comes closest to having the RTC's 1Hz squarewave output match the frequency of GPS PPS. If I can rig it up so the GPS antenna is in the clear, I need to see if the aging solution changes in the freezer, and by how much.
But even if the built-in adjustment isn't all that great, it may be possible to apply your own formula that makes it work better. You can read the temperature from registers on the DS3231, and calculate an adjustment. I think this would have to be set up in advance for each individual part, so getting a logger ready to deploy might require a good bit of testing.
The big cost with GPS is in power. Mine runs at 45mA. So you don't want to be powering it up very often. A DCF77 or WWVB receiver would use less power, but reception would be less reliable. For most uses though, I think it's possible to rely primarily on the RTC and still have really good timekeeping.