I'll assume breadboard = Super-Strip, or equivalent as shown below.
First off, you are better off using a perfboard for the 1.7 MHz square wave frequency you intend to use which has significant frequency components in to the tens-of-MHz. The switching speed of a FET is such that breadboards don't do well. Copper tape can be used to create low impedance planes for your power connections on a perfboard.
Image of perfboard project showing top & bottom of board. Large copper tape area is ground.
Addressing your other concerns about power limitations on a breadboard (perhaps you want to test your circuit at a much lower frequency), power is a hard to quantify parameter on a breadboard. You are most interested in how hot the components will get which is directly relatable to power dissipation of the component, not the breadboard. If the resistor leads get too hot, it will melt the breadboard plastic. If you make the leads longer, the temperature of the leads at the breadboard will be less, however, the inductance of the leads will increase which could cause bad ringing and possibly do something bad.
The other concern is how much current the contact strips on the breadboard can handle. The contact strips will heat up when current is passed through them, how much I do not know.
Cheap breadboards often have high contact resistance which can cause additional heating of the contacts.