Improve Rise Time on 1Hz Signal
You don't say what signal it is you are driving, but most of the inputs in the datasheet you linked to specify a maximum rise time of 50ns. The larger resistor and any input capacitance will certainly exceed this rise time requirement.

A simple CMOS buffer will help by squaring up the edges as it has a much higher drive strength than the pull-up resistor.

The key is to find one with a low input capacitance which will allow you to use a higher resistance pull-up which while keeping the rise time at the input of the buffer reasonable.

As an example the SN74LVC1G34 has an input capacitance of around 3pF. Even with that low of a capacitance, you are still looking at a 2-3μs rise time at the buffer input. This may well be acceptable, but as you can see, it is still very slow.

You can also use a Schmitt trigger. That will mean that if there is a very long rise time on the input signal you will have better noise immunity to stop the output toggling at high frequency during the transition. But again, you need to make sure the input capacitance is minimised.

Another alternative would be to get an ultra-low power comparator. Microchip do some nano-amp comparators. I've used some of these in the past coupled with 10MΩ bias resistors to create a low power draw Schmitt trigger for a coin cell application. The whole circuit including resistors draws less than a 1μA (it was too low for the ammeter I was using to measure). You can tune the resistors to match the required hysteresis, but this was the circuit I used in that application: