Yes, you can do that although I don't know what the monthly fee will be, it could be a little less than that. I would not do it, I would buy lifetime service. First try to get lifetime service for the TiVo Premiere, you might be able to get that for $99, call TiVo and ask.
If the answer is no, you can buy a TiVo Roamio refurbished with lifetime for $300 now, this deal is rumored to be available for a couple more days, could last longer or could end at any time as far as I know. Act fast.
Home Theater - OTA TiVo Roamio/500GB/NSZ-GS8 GTV
MBR - OTA TiVoHD/660GB/NSZ-GT1 GTV
Den - OTA TiVo Premiere/2TB/NSZ-GT1