NATO has no interest in invading Russia in wintertime or at any other time. NATO is a defensive treaty organisation that would only be involved in military activities in the event that one or more of its members states were attacked. If this attack was carried out by Russia, NATO forces would repel it, defeat the forces which carried it out and, in the event of having to carry out these activities on Russian soil, would negotiate a withdrawal from sovereign Russian territory as soon as hostilities could be halted and assured not to be restarted by Russia. Wanting to occupy any sizeable amount of Russian territory is not something that any NATO commander would want to contemplate not would NATO member stat6esd want to commit to such a policy. Liberating Russian occupied territory and turning it over to its rightful owners is another matter but the factors of winter warfare which destroyed the Wehrmacht in WWll just would not apply to NATO forces which would not have the objectives of conquest in their battle plans.
I suspect that this question may be Russian trolling as it makes the sort of military assumptions which apply to Russia and not to NATO. Russian forces are organised, armed and trained in aggressive invasive warfare while NATO concentrates on effective defensive strategies. Russian military leadership sees defence as best served by attack and has no qualms about attacking first and permanently occupying captured territory. They obviously find it difficult to believe that foolish NATO forces would wait to be attacked before committing to battle. But that?s the difference between the two blocks which is inadvertently exposed in this question. Read Also : What is the maximum salary of a digital marketer in united states?